Allow implementations of the match() callback in struct bus_type to
return errors and if it's -EPROBE_DEFER then queue the device for
deferred probing.
This is useful to buses such as AMBA in which devices are registered
before their matching information can be retrieved from the HW
(typically because a clock driver hasn't probed yet).
[changed if-else code structure, adjusted documentation to match the code,
extended comments]
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If device_is_bound() is called on a device that's not been registered
yet, it will attepmt to dereference dev->p which is NULL, so avoid
that by checking dev->p in there against NULL.
Fixes: 6b9cb42752 "device core: add device_is_bound()"
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a suitable prepare callback cannot be found for a given device and
its driver has no PM callbacks at all, assume that it can go direct to
complete when the system goes to sleep.
The reason for this is that there's lots of devices in a system that do
no PM at all and there's no reason for them to prevent their ancestors
to do direct_complete if they can support it.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Adds a function that tells whether a device is already bound to a
driver.
This is needed to warn when there is an attempt to change the PM domain
of a device that has finished probing already. The reason why we want to
enforce that is because in the general case that can cause problems and
also that we can simplify code quite a bit if we can always assume that.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of
a probe failure. In the result there might be problems, such as some resources
that had been allocated will continue to be allocated and therefore lead to a
resource leak.
Introduce a new notification to inform the subscriber that ->probe() failed. Do
the same in case of failed device_bind_driver() call.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are two common expectations among several subsystems/drivers that
deploys runtime PM support, but which isn't met by the driver core.
Expectation 1)
At ->probe() the subsystem/driver expects the runtime PM status of the
device to be RPM_SUSPENDED, which is the initial status being assigned at
device registration.
This expectation is especially common among some of those subsystems/
drivers that manages devices with an attached PM domain, as those requires
the ->runtime_resume() callback at the PM domain level to be invoked
during ->probe().
Moreover these subsystems/drivers entirely relies on runtime PM resources
being managed at the PM domain level, thus don't implement their own set
of runtime PM callbacks.
These are two scenarios that suffers from this unmet expectation.
i) A failed ->probe() sequence requests probe deferral:
->probe()
...
pm_runtime_enable()
pm_runtime_get_sync()
...
err:
pm_runtime_put()
pm_runtime_disable()
...
As there are no guarantees that such sequence turns the runtime PM status
of the device into RPM_SUSPENDED, the re-trying ->probe() may start with
the status in RPM_ACTIVE.
In such case the runtime PM core won't invoke the ->runtime_resume()
callback because of a pm_runtime_get_sync(), as it considers the device to
be already runtime resumed.
ii) A driver re-bind sequence:
At driver unbind, the subsystem/driver's >remove() callback invokes a
sequence of runtime PM APIs, to undo actions during ->probe() and to put
the device into low power state.
->remove()
...
pm_runtime_put()
pm_runtime_disable()
...
Similar as in the failing ->probe() case, this sequence don't guarantee
the runtime PM status of the device to turn into RPM_SUSPENDED.
Trying to re-bind the driver thus causes the same issue as when re-trying
->probe(), in the probe deferral scenario.
Expectation 2)
Drivers that invokes the pm_runtime_irq_safe() API during ->probe(),
triggers the runtime PM core to increase the usage count for the device's
parent and permanently make it runtime resumed.
The usage count is only dropped at device removal, which also allows it to
be runtime suspended again.
A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus
once more triggers the usage count of the device's parent to be increased.
This leads to not only an imbalance issue of the usage count of the
device's parent, but also to keep it runtime resumed permanently even if
->probe() fails.
To address these issues, let's change the policy of the driver core to
meet these expectations. More precisely, at ->probe() failures and driver
unbind, restore the initial states of runtime PM.
Although to still allow subsystem's to control PM for devices that doesn't
->probe() successfully, don't restore the initial states unless runtime PM
is disabled.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is unsafe [1] if probing of devices will happen during suspend or
hibernation and system behavior will be unpredictable in this case.
So, let's prohibit device's probing in dpm_prepare() and defer their
probing instead. The normal behavior will be restored in
dpm_complete().
This patch introduces new DD core APIs:
device_block_probing()
It will disable probing of devices and defer their probes instead.
device_unblock_probing()
It will restore normal behavior and trigger re-probing of deferred
devices.
[1] https://lkml.org/lkml/2015/9/11/554
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For pinctrl the "default" state is applied to pins before the driver's
probe function is called. This is normally a sensible thing to do,
but in some cases can cause problems. That's because the pins will
change state before the driver is given a chance to program how those
pins should behave.
As an example you might have a regulator that is controlled by a PWM
(output high = high voltage, output low = low voltage). The firmware
might leave this pin as driven high. If we allow the driver core to
reconfigure this pin as a PWM pin before the PWM's probe function runs
then you might end up running at too low of a voltage while we probe.
Let's introudce a new "init" state. If this is defined we'll set
pinctrl to this state before probe and then "default" after probe
(unless the driver explicitly changed states already).
An alternative idea that was thought of was to use the pre-existing
"sleep" or "idle" states and add a boolean property that we should
start in that mode. This was not done because the "init" state is
needed for correctness and those other states are only present (and
only transitioned in to and out of) when (optional) power management
is enabled.
Changes in v3:
- Moved declarations to pinctrl/devinfo.h
- Fixed author/SoB
Changes in v2:
- Added comment to pinctrl_init_done() as per Linus W.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
- ACPICA update to upstream revision 20150818 including method
tracing extensions to allow more in-depth AML debugging in the
kernel and a number of assorted fixes and cleanups (Bob Moore,
Lv Zheng, Markus Elfring).
- ACPI sysfs code updates and a documentation update related to
AML method tracing (Lv Zheng).
- ACPI EC driver fix related to serialized evaluations of _Qxx
methods and ACPI tools updates allowing the EC userspace tool
to be built from the kernel source (Lv Zheng).
- ACPI processor driver updates preparing it for future
introduction of CPPC support and ACPI PCC mailbox driver
updates (Ashwin Chaugule).
- ACPI interrupts enumeration fix for a regression related
to the handling of IRQ attribute conflicts between MADT
and the ACPI namespace (Jiang Liu).
- Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar).
- ACPI device registration code reorganization to separate the
sysfs-related code and bus type operations from the rest (Rafael
J Wysocki).
- Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
- ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups
(Pan Xinhui, Rafael J Wysocki).
- cpufreq core cleanups on top of the previous changes allowing it
to preseve its sysfs directories over system suspend/resume (Viresh
Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
- cpufreq fixes and cleanups related to governors (Viresh Kumar).
- cpufreq updates (core and the cpufreq-dt driver) related to the
turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
- New DT bindings for Operating Performance Points (OPP), support
for them in the OPP framework and in the cpufreq-dt driver plus
related OPP framework fixes and cleanups (Viresh Kumar).
- cpufreq powernv driver updates (Shilpasri G Bhat).
- New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
- Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
- intel_pstate driver updates including Skylake-S support, support
for enabling HW P-states per CPU and an additional vendor bypass
list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
- cpuidle core fixes related to the handling of coupled idle states
(Xunlei Pang).
- intel_idle driver updates including Skylake Client support and
support for freeze-mode-specific idle states (Len Brown).
- Driver core updates related to power management (Andy Shevchenko,
Rafael J Wysocki).
- Generic power domains framework fixes and cleanups (Jon Hunter,
Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
- Device PM QoS framework update to allow the latency tolerance
setting to be exposed to user space via sysfs (Mika Westerberg).
- devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
- System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
- rockchip-io AVS support updates (Heiko Stuebner).
- PM core clocks support fixup (Colin Ian King).
- Power capping RAPL driver update including support for Skylake H/S
and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
- Generic device properties framework fixes related to the handling
of static (driver-provided) property sets (Andy Shevchenko).
- turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
Shreyas B Prabhu).
/
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Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"From the number of commits perspective, the biggest items are ACPICA
and cpufreq changes with the latter taking the lead (over 50 commits).
On the cpufreq front, there are many cleanups and minor fixes in the
core and governors, driver updates etc. We also have a new cpufreq
driver for Mediatek MT8173 chips.
ACPICA mostly updates its debug infrastructure and adds a number of
fixes and cleanups for a good measure.
The Operating Performance Points (OPP) framework is updated with new
DT bindings and support for them among other things.
We have a few updates of the generic power domains framework and a
reorganization of the ACPI device enumeration code and bus type
operations.
And a lot of fixes and cleanups all over.
Included is one branch from the MFD tree as it contains some
PM-related driver core and ACPI PM changes a few other commits are
based on.
Specifics:
- ACPICA update to upstream revision 20150818 including method
tracing extensions to allow more in-depth AML debugging in the
kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
Zheng, Markus Elfring).
- ACPI sysfs code updates and a documentation update related to AML
method tracing (Lv Zheng).
- ACPI EC driver fix related to serialized evaluations of _Qxx
methods and ACPI tools updates allowing the EC userspace tool to be
built from the kernel source (Lv Zheng).
- ACPI processor driver updates preparing it for future introduction
of CPPC support and ACPI PCC mailbox driver updates (Ashwin
Chaugule).
- ACPI interrupts enumeration fix for a regression related to the
handling of IRQ attribute conflicts between MADT and the ACPI
namespace (Jiang Liu).
- Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
Kasagar).
- ACPI device registration code reorganization to separate the
sysfs-related code and bus type operations from the rest (Rafael J
Wysocki).
- Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
- ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
Xinhui, Rafael J Wysocki).
- cpufreq core cleanups on top of the previous changes allowing it to
preseve its sysfs directories over system suspend/resume (Viresh
Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
- cpufreq fixes and cleanups related to governors (Viresh Kumar).
- cpufreq updates (core and the cpufreq-dt driver) related to the
turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
- New DT bindings for Operating Performance Points (OPP), support for
them in the OPP framework and in the cpufreq-dt driver plus related
OPP framework fixes and cleanups (Viresh Kumar).
- cpufreq powernv driver updates (Shilpasri G Bhat).
- New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
- Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
- intel_pstate driver updates including Skylake-S support, support
for enabling HW P-states per CPU and an additional vendor bypass
list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
- cpuidle core fixes related to the handling of coupled idle states
(Xunlei Pang).
- intel_idle driver updates including Skylake Client support and
support for freeze-mode-specific idle states (Len Brown).
- Driver core updates related to power management (Andy Shevchenko,
Rafael J Wysocki).
- Generic power domains framework fixes and cleanups (Jon Hunter,
Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
- Device PM QoS framework update to allow the latency tolerance
setting to be exposed to user space via sysfs (Mika Westerberg).
- devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
- System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
- rockchip-io AVS support updates (Heiko Stuebner).
- PM core clocks support fixup (Colin Ian King).
- Power capping RAPL driver update including support for Skylake H/S
and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
- Generic device properties framework fixes related to the handling
of static (driver-provided) property sets (Andy Shevchenko).
- turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
Shreyas B Prabhu)"
* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
cpufreq: speedstep-lib: Use monotonic clock
cpufreq: powernv: Increase the verbosity of OCC console messages
cpufreq: sfi: use kmemdup rather than duplicating its implementation
cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
cpufreq: remove redundant 'policy' field from user_policy
cpufreq: remove redundant 'governor' field from user_policy
cpufreq: update user_policy.* on success
cpufreq: use memcpy() to copy policy
cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
cpufreq: mediatek: Add MT8173 cpufreq driver
dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
PM / Domains: Fix typo in description of genpd_dev_pm_detach()
PM / Domains: Remove unusable governor dummies
PM / Domains: Make pm_genpd_init() available to modules
PM / domains: Align column headers and data in pm_genpd_summary output
powercap / RAPL: disable the 2nd power limit properly
tools: cpupower: Fix error when running cpupower monitor
PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
PM / OPP: Fix static checker warning (broken 64bit big endian systems)
...
Now device's shutdown sequence is performed in reverse order of their
registration in devices_kset list and this sequence corresponds to the
reverse device's creation order. So, devices_kset data tracks
"parent<-child" device's dependencies only.
Unfortunately, that's not enough and causes problems in case of
implementing board's specific shutdown procedures. For example [1]:
"DRA7XX_evm uses PCF8575 and one of the PCF output lines feeds to
MMC/SD and this line should be driven high in order for the MMC/SD to
be detected. This line is modelled as regulator and the hsmmc driver
takes care of enabling and disabling it. In the case of 'reboot',
during shutdown path as part of it's cleanup process the hsmmc driver
disables this regulator. This makes MMC boot not functional."
To handle this issue the .shutdown() callback could be implemented
for PCF8575 device where corresponding GPIO pins will be configured to
states, required for correct warm/cold reset. This can be achieved
only when all .shutdown() callbacks have been called already for all
PCF8575's consumers. But devices_kset is not filled correctly now:
devices_kset: Device61 4e000000.dmm
devices_kset: Device62 48070000.i2c
devices_kset: Device63 48072000.i2c
devices_kset: Device64 48060000.i2c
devices_kset: Device65 4809c000.mmc
...
devices_kset: Device102 fixedregulator-sd
...
devices_kset: Device181 0-0020 // PCF8575
devices_kset: Device182 gpiochip496
devices_kset: Device183 0-0021 // PCF8575
devices_kset: Device184 gpiochip480
As can be seen from above .shutdown() callback for PCF8575 will be called
before its consumers, which, in turn means, that any changes of PCF8575
GPIO's pins will be or unsafe or overwritten later by GPIO's consumers.
The problem can be solved if devices_kset list will be filled not only
according device creation order, but also according device's probing
order to track "supplier<-consumer" dependencies also.
Hence, as a fix, lets add devices_kset_move_last(),
devices_kset_move_before(), devices_kset_move_after() and call them
from device_move() and also add call of devices_kset_move_last() in
really_probe(). After this change all entries in devices_kset will
be sorted according to device's creation ("parent<-child") and
probing ("supplier<-consumer") order.
devices_kset after:
devices_kset: Device121 48070000.i2c
devices_kset: Device122 i2c-0
...
devices_kset: Device147 regulator.24
devices_kset: Device148 0-0020
devices_kset: Device149 gpiochip496
devices_kset: Device150 0-0021
devices_kset: Device151 gpiochip480
devices_kset: Device152 0-0019
...
devices_kset: Device372 fixedregulator-sd
devices_kset: Device373 regulator.29
devices_kset: Device374 4809c000.mmc
devices_kset: Device375 mmc0
[1] http://www.spinics.net/lists/linux-mmc/msg29825.html
Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the parent is still suspended when driver probe is
attempted, the result may be failure.
For example, if the parent is a PCI MFD device that has been
suspended when we try to probe our device, any register
reads will return 0xffffffff.
To fix the problem, making sure the parent is always awake
before attempting driver probe.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Commit f2411da746 ("driver-core: add driver module asynchronous probe
support") broke build in case modules are disabled, because in this case
"struct module" is not defined and we can't dereference it. Let's define
module_requested_async_probing() helper and stub it out if modules are
disabled.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is only used within dd.c and thus need not be global.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are drivers that can not be probed asynchronously. One such group
is platform drivers registered with platform_driver_probe(), which
expects driver's probe routine be discarded after the driver has been
registered and initial binding attempt executed. Also
platform_driver_probe() an error when no devices were bound to the
driver, allowing failing to load such driver module altogether.
Other drivers do not work well with asynchronous probing because of
driver bug or not optimal driver organization.
To allow using such drivers even when user requests asynchronous probing
as default boot strategy, let's allow them to opt out.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some init systems may wish to express the desire to have device drivers
run their probe() code asynchronously. This implements support for this
and allows userspace to request async probe as a preference through a
generic shared device driver module parameter, async_probe.
Implementation for async probe is supported through a module parameter
given that since synchronous probe has been prevalent for years some
userspace might exist which relies on the fact that the device driver
will probe synchronously and the assumption that devices it provides
will be immediately available after this.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some devices take a long time when initializing, and not all drivers are
suited to initialize their devices when they are open. For example,
input drivers need to interrogate their devices in order to publish
device's capabilities before userspace will open them. When such drivers
are compiled into kernel they may stall entire kernel initialization.
This change allows drivers request for their probe functions to be
called asynchronously during driver and device registration (manual
binding is still synchronous). Because async_schedule is used to perform
asynchronous calls module loading will still wait for the probing to
complete.
Note that the end goal is to make the probing asynchronous by default,
so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary
measure that allows us to speed up boot process while we validating and
fixing the rest of the drivers and preparing userspace.
This change is based on earlier patch by "Luis R. Rodriguez"
<mcgrof@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Generic PM domains support update including new PM domain
callbacks to handle device initialization better (Russell King,
Rafael J Wysocki, Kevin Hilman).
- Unified device properties API update including a new mechanism
for accessing data provided by platform initialization code
(Rafael J Wysocki, Adrian Hunter).
- ARM cpuidle update including ARM32/ARM64 handling consolidation
(Daniel Lezcano).
- intel_idle update including support for the Silvermont Core in
the Baytrail SOC and for the Airmont Core in the Cherrytrail and
Braswell SOCs (Len Brown, Mathias Krause).
- New cpufreq driver for Hisilicon ACPU (Leo Yan).
- intel_pstate update including support for the Knights Landing
chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
- QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
- powernv cpufreq driver update (Shilpasri G Bhat).
- devfreq update including Tegra support changes (Tomeu Vizoso,
MyungJoo Ham, Chanwoo Choi).
- powercap RAPL (Running-Average Power Limit) driver update
including support for Intel Broadwell server chips (Jacob Pan,
Mathias Krause).
- ACPI device enumeration update related to the handling of the
special PRP0001 device ID allowing DT-style 'compatible' property
to be used for ACPI device identification (Rafael J Wysocki).
- ACPI EC driver update including limited _DEP support (Lan Tianyu,
Lv Zheng).
- ACPI backlight driver update including a new mechanism to allow
native backlight handling to be forced on non-Windows 8 systems
and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
- New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
- Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
- Fixes related to suspend-to-idle for the iTCO watchdog driver and
the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
- PM tracing support for the suspend phase of system suspend/resume
transitions (Zhonghui Fu).
- Configurable delay for the system suspend/resume testing facility
(Brian Norris).
- PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
/
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Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"These are mostly fixes and cleanups all over, although there are a few
items that sort of fall into the new feature category.
First off, we have new callbacks for PM domains that should help us to
handle some issues related to device initialization in a better way.
There also is some consolidation in the unified device properties API
area allowing us to use that inferface for accessing data coming from
platform initialization code in addition to firmware-provided data.
We have some new device/CPU IDs in a few drivers, support for new
chips and a new cpufreq driver too.
Specifics:
- Generic PM domains support update including new PM domain callbacks
to handle device initialization better (Russell King, Rafael J
Wysocki, Kevin Hilman)
- Unified device properties API update including a new mechanism for
accessing data provided by platform initialization code (Rafael J
Wysocki, Adrian Hunter)
- ARM cpuidle update including ARM32/ARM64 handling consolidation
(Daniel Lezcano)
- intel_idle update including support for the Silvermont Core in the
Baytrail SOC and for the Airmont Core in the Cherrytrail and
Braswell SOCs (Len Brown, Mathias Krause)
- New cpufreq driver for Hisilicon ACPU (Leo Yan)
- intel_pstate update including support for the Knights Landing chip
(Dasaratharaman Chandramouli, Kristen Carlson Accardi)
- QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)
- powernv cpufreq driver update (Shilpasri G Bhat)
- devfreq update including Tegra support changes (Tomeu Vizoso,
MyungJoo Ham, Chanwoo Choi)
- powercap RAPL (Running-Average Power Limit) driver update including
support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)
- ACPI device enumeration update related to the handling of the
special PRP0001 device ID allowing DT-style 'compatible' property
to be used for ACPI device identification (Rafael J Wysocki)
- ACPI EC driver update including limited _DEP support (Lan Tianyu,
Lv Zheng)
- ACPI backlight driver update including a new mechanism to allow
native backlight handling to be forced on non-Windows 8 systems and
a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)
- New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)
- Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)
- Fixes related to suspend-to-idle for the iTCO watchdog driver and
the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)
- PM tracing support for the suspend phase of system suspend/resume
transitions (Zhonghui Fu)
- Configurable delay for the system suspend/resume testing facility
(Brian Norris)
- PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"
* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
ACPI / scan: Rework modalias creation when "compatible" is present
intel_idle: mark cpu id array as __initconst
powercap / RAPL: mark rapl_ids array as __initconst
powercap / RAPL: add ID for Broadwell server
intel_pstate: Knights Landing support
intel_pstate: remove MSR test
cpufreq: fix qoriq uniprocessor build
ACPI / scan: Take the PRP0001 position in the list of IDs into account
ACPI / scan: Simplify acpi_match_device()
ACPI / scan: Generalize of_compatible matching
device property: Introduce firmware node type for platform data
device property: Make it possible to use secondary firmware nodes
PM / watchdog: iTCO: stop watchdog during system suspend
cpufreq: hisilicon: add acpu driver
ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
cpufreq: powernv: Report cpu frequency throttling
intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
intel_idle: Update support for Silvermont Core in Baytrail SOC
PM / devfreq: tegra: Register governor on module init
...
Currently probe deferral prints a message every time a device requests
deferral at info severity (which is displayed by default). This can have
an impact on system boot times with serial consoles and is generally quite
noisy.
Since subsystems and drivers should already be logging the specific reason
for probe deferral in order to aid users in understanding problems the
messages from the driver core should be redundant lower the severity of
the messages printed, cutting down on the volume of output on the console.
This does mean that if the drivers and subsystems aren't doing a good job
we get no output on the console by default. Ideally we'd be able to arrange
to print if nothing else printed, though that's a little fun. Even better
would be to come up with a mechanism that explicitly does dependencies so
we don't have to keep polling and erroring.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are series of comparisons of the 'ret' variable on the failure path of
really_probe(), so the *switch* statement seems more appropriate there.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If PM domains are in use, it may be necessary to prepare the code
handling a PM domain for driver probing. For example, in some
cases device drivers rely on the ability to power on the devices
with the help of the IO runtime PM framework and the PM domain
code needs to be ready for that. Also, if that code has not been
fully initialized yet, the driver probing should be deferred.
Moreover, after the probing is complete, it may be necessary to
put the PM domain in question into the state reflecting the current
needs of the devices in it, for example, so that power is not drawn
in vain. The same should be done after removing a driver from
a device, as the PM domain state may need to be changed to reflect
the new situation.
For these reasons, introduce new PM domain callbacks, ->activate,
->sync and ->dismiss called, respectively, before probing for a
device driver, after the probing has completed successfully and
if the probing has failed or the driver has been removed.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The deferred_probe_work_func() function is locally scoped, therefore an
associated kerneldoc comment isn't very useful. Replace the kerneldoc
opening marker (/**) with a regular block comment marker (/*) to avoid
the comment from being parsed by kerneldoc. This gets rid of a warning
caused by a missing description for the "work" argument.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dev_set_drvdata and dev_get_drvdata are now simple enough again that
we can inline them as they used to be before commit b40284378.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no point in calling dev_get_drvdata without a valid device.
So checking for dev == NULL is pointless. If such a check is ever
needed - which I doubt - the driver should do it before calling
dev_get_drvdata.
We were returning NULL if dev was NULL, which the caller certainly did
not expect anyway, so that was only delaying the crash if the caller
is not paying attention.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dev_set_drvdata can no longer fail, so it could return void.
All callers have hopefully been updated to no longer check for the
return value.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Having to allocate memory as part of dev_set_drvdata() is a problem
because that memory may never get freed if the device itself is not
created. So move driver_data back to struct device.
This is a partial revert of commit b4028437.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the kernel is built with CONFIG_PREEMPT it is possible to reach a state
when all modules loaded but some driver still stuck in the deferred list
and there is a need for external event to kick the deferred queue to probe
these drivers.
The issue has been observed on embedded systems with CONFIG_PREEMPT enabled,
audio support built as modules and using nfsroot for root filesystem.
The following log fragment shows such sequence when all audio modules
were loaded but the sound card is not present since the machine driver has
failed to probe due to missing dependency during it's probe.
The board is am335x-evmsk (McASP<->tlv320aic3106 codec) with davinci-evm
machine driver:
...
[ 12.615118] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: ENTER
[ 12.719969] davinci_evm sound.3: davinci_evm_probe: ENTER
[ 12.725753] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card
[ 12.753846] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component
[ 12.922051] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component DONE
[ 12.950839] davinci_evm sound.3: ASoC: platform (null) not registered
[ 12.957898] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card DONE (-517)
[ 13.099026] davinci-mcasp 4803c000.mcasp: Kicking the deferred list
[ 13.177838] davinci-mcasp 4803c000.mcasp: really_probe: probe_count = 2
[ 13.194130] davinci_evm sound.3: snd_soc_register_card failed (-517)
[ 13.346755] davinci_mcasp_driver_init: LEAVE
[ 13.377446] platform sound.3: Driver davinci_evm requests probe deferral
[ 13.592527] platform sound.3: really_probe: probe_count = 0
In the log the machine driver enters it's probe at 12.719969 (this point it
has been removed from the deferred lists). McASP driver already executing
it's probing (since 12.615118).
The machine driver tries to construct the sound card (12.950839) but did
not found one of the components so it fails. After this McASP driver
registers all the ASoC components (the machine driver still in it's probe
function after it failed to construct the card) and the deferred work is
prepared at 13.099026 (note that this time the machine driver is not in the
lists so it is not going to be handled when the work is executing).
Lastly the machine driver exit from it's probe and the core places it to
the deferred list but there will be no other driver going to load and the
deferred queue is not going to be kicked again - till we have external event
like connecting USB stick, etc.
The proposed solution is to try the deferred queue once more when the last
driver is asking for deferring and we had drivers loaded while this last
driver was probing.
This way we can avoid drivers stuck in the deferred queue.
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stable <stable@vger.kernel.org> # v3.4+
pr_debug() parameters are reverse order of format string
Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit fa180eb448 (PM / Runtime: Idle devices asynchronously after
probe|release) modified __device_release_driver() to call
pm_runtime_put(dev) instead of pm_runtime_put_sync(dev) before
detaching the driver from the device. However, that was a mistake,
because pm_runtime_put(dev) causes rpm_idle() to be queued up and
the driver may be gone already when that function is executed.
That breaks the assumptions the drivers have the right to make
about the core's behavior on the basis of the existing documentation
and actually causes problems to happen, so revert that part of
commit fa180eb448 and restore the previous behavior of
__device_release_driver().
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Fixes: fa180eb448 (PM / Runtime: Idle devices asynchronously after probe|release)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Putting devices into idle|suspend in a synchronous manner means we are
waiting for each device to become idle|suspended before the probe|release
is fully done.
This patch switch to use the asynchronous runtime PM API:s instead and
thus improves the parallelism since we can move on and handle the next
device in queue in an earlier phase.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers all
over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
If you need me to provide a merged tree to handle these resolutions,
please let me know.
Other than those patches, there's not much here, some minor fixes and
updates.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg Kroah-Hartman:
"Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers
all over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
Other than those patches, there's not much here, some minor fixes and
updates"
Fix up trivial conflicts
* tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits)
base: memory: fix soft/hard_offline_page permissions
drivercore: Fix ordering between deferred_probe and exiting initcalls
backlight: fix class_find_device() arguments
TTY: mark tty_get_device call with the proper const values
driver-core: constify data for class_find_device()
firmware: Ignore abort check when no user-helper is used
firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER
firmware: Make user-mode helper optional
firmware: Refactoring for splitting user-mode helper code
Driver core: treat unregistered bus_types as having no devices
watchdog: Convert to devm_ioremap_resource()
thermal: Convert to devm_ioremap_resource()
spi: Convert to devm_ioremap_resource()
power: Convert to devm_ioremap_resource()
mtd: Convert to devm_ioremap_resource()
mmc: Convert to devm_ioremap_resource()
mfd: Convert to devm_ioremap_resource()
media: Convert to devm_ioremap_resource()
iommu: Convert to devm_ioremap_resource()
drm: Convert to devm_ioremap_resource()
...
One of the side effects of deferred probe is that some drivers which
used to be probed before initcalls completed are now happening slightly
later. This causes two problems.
- If a console driver gets deferred, then it may not be ready when
userspace starts. For example, if a uart depends on pinctrl, then the
uart will get deferred and /dev/console will not be available
- __init sections will be discarded before built-in drivers are probed.
Strictly speaking, __init functions should not be called in a drivers
__probe path, but there are a lot of drivers (console stuff again)
that do anyway. In the past it was perfectly safe to do so because all
built-in drivers got probed before the end of initcalls.
This patch fixes the problem by forcing the first pass of the deferred
list to complete at late_initcall time. This is late enough to catch the
drivers that are known to have the above issues.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@vger.kernel.org> # 3.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This makes the device core auto-grab the pinctrl handle and set
the "default" (PINCTRL_STATE_DEFAULT) state for every device
that is present in the device model right before probe. This will
account for the lion's share of embedded silicon devcies.
A modification of the semantics for pinctrl_get() is also done:
previously if the pinctrl handle for a certain device was already
taken, the pinctrl core would return an error. Now, since the
core may have already default-grabbed the handle and set its
state to "default", if the handle was already taken, this will
be disregarded and the located, previously instanitated handle
will be returned to the caller.
This way all code in drivers explicitly requesting their pinctrl
handlers will still be functional, and drivers that want to
explicitly retrieve and switch their handles can still do that.
But if the desired functionality is just boilerplate of this
type in the probe() function:
struct pinctrl *p;
p = devm_pinctrl_get_select_default(&dev);
if (IS_ERR(p)) {
if (PTR_ERR(p) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_warn(&dev, "no pinctrl handle\n");
}
The discussion began with the addition of such boilerplate
to the omap4 keypad driver:
http://marc.info/?l=linux-input&m=135091157719300&w=2
A previous approach using notifiers was discussed:
http://marc.info/?l=linux-kernel&m=135263661110528&w=2
This failed because it could not handle deferred probes.
This patch alone does not solve the entire dilemma faced:
whether code should be distributed into the drivers or
if it should be centralized to e.g. a PM domain. But it
solves the immediate issue of the addition of boilerplate
to a lot of drivers that just want to grab the default
state. As mentioned, they can later explicitly retrieve
the handle and set different states, and this could as
well be done by e.g. PM domains as it is only related
to a certain struct device * pointer.
ChangeLog v4->v5 (Stephen):
- Simplified the devicecore grab code.
- Deleted a piece of documentation recommending that pins
be mapped to a device rather than hogged.
ChangeLog v3->v4 (Linus):
- Drop overzealous NULL checks.
- Move kref initialization to pinctrl_create().
- Seeking Tested-by from Stephen Warren so we do not disturb
the Tegra platform.
- Seeking ACK on this from Greg (and others who like it) so I
can merge it through the pinctrl subsystem.
ChangeLog v2->v3 (Linus):
- Abstain from using IS_ERR_OR_NULL() in the driver core,
Russell recently sent a patch to remove it. Handle the
NULL case explicitly even though it's a bogus case.
- Make sure we handle probe deferral correctly in the device
core file. devm_kfree() the container on error so we don't
waste memory for devices without pinctrl handles.
- Introduce reference counting into the pinctrl core using
<linux/kref.h> so that we don't release pinctrl handles
that have been obtained for two or more places.
ChangeLog v1->v2 (Linus):
- Only store a pointer in the device struct, and only allocate
this if it's really used by the device.
Cc: Felipe Balbi <balbi@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Mitch Bradley <wmb@firmworks.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Rickard Andersson <rickard.andersson@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to
correctly handle deferred probe. Removed admonition from docs not to use
pinctrl hogs for devices]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The pm_runtime_get_noresume() calls before really_probe() and
before executing __device_attach() for each driver on the
device's bus cause problems to happen if probing fails and if the
driver has enabled runtime PM for the device in its .probe()
callback. Namely, in that case, if the device has been resumed
by the driver after enabling its runtime PM and if it turns out that
.probe() should return an error, the driver is supposed to suspend
the device and disable its runtime PM before exiting .probe().
However, because the device's runtime PM usage counter was
incremented by the core before calling .probe(), the driver's attempt
to suspend the device will not succeed and the device will remain in
the full-power state after the failing .probe() has returned.
To fix this issue, remove the pm_runtime_get_noresume() calls from
driver_probe_device() and from device_attach() and replace the
corresponding pm_runtime_put_sync() calls with pm_runtime_idle()
to preserve the existing behavior (which is to check if the device
is idle and to suspend it eventually in that case after probing).
Reported-and-tested-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When deferred probe was originally added the idea was that devices which
defer their probes would move themselves to the end of dpm_list in order
to try to keep the assumptions that we're making about the list being in
roughly the order things should be suspended correct. However this hasn't
been what's been happening and doing it requires a lot of duplicated code
to do the moves.
Instead take a simple, brute force solution and have the deferred probe
code push devices to the end of dpm_list before it retries the probe. This
does mean we lock the dpm_list a bit more often but it's very simple and
the code shouldn't be a fast path. We do the move with the deferred mutex
dropped since doing things with fewer locks held simultaneously seems like
a good idea.
This approach was most recently suggested by Grant Likely.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Grant Likely <grant.likely@secretlab.ca>,
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This picks up the big printk fixes, and resolves a merge issue with:
drivers/extcon/extcon_gpio.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1) drvdata is for a driver to store a pointer to driver specific data
2) If no driver is bound, there is no driver specific data associated with
the device
3) Thus logically drvdata should be NULL if no driver is bound.
But many drivers don't clear drvdata on device_release, or set drvdata
early on in probe and leave it set on probe error. Both of which results
in a dangling pointer in drvdata.
This patch enforce for drvdata to be NULL after device_release or on probe
failure.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If driver requests probe deferral,
it will be added to deferred_probe_pending_list
by driver_deferred_probe_add(), but, it used list_add().
Because of that, deferred probe will be run as reversed order.
This patch uses list_add_tail(), and solved this issue.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Came in in the deferred probe patch, quick, clean them up before a
kernel janitor finds them and sends me 4 individual patches to fix them
up...
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nothing outside of the driver core needs to get to the deferred probe
pointer, so move it inside the private area of 'struct device' so no one
tries to mess around with it.
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow drivers to report at probe time that they cannot get all the resources
required by the device, and should be retried at a later time.
This should completely solve the problem of getting devices
initialized in the right order. Right now this is mostly handled by
mucking about with initcall ordering which is a complete hack, and
doesn't even remotely handle the case where device drivers are in
modules. This approach completely sidesteps the issues by allowing
driver registration to occur in any order, and any driver can request
to be retried after a few more other drivers get probed.
v4: - Integrate Manjunath's addition of a separate workqueue
- Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral
- Update comment blocks to reflect how the code really works
v3: - Hold off workqueue scheduling until late_initcall so that the bulk
of driver probes are complete before we start retrying deferred devices.
- Tested with simple use cases. Still needs more testing though.
Using it to get rid of the gpio early_initcall madness, or to replace
the ASoC internal probe deferral code would be ideal.
v2: - added locking so it should no longer be utterly broken in that regard
- remove device from deferred list at device_del time.
- Still completely untested with any real use case, but has been
boot tested.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dilan Lee <dilee@nvidia.com>
Cc: Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DEBUG_DRIVER is activated, be verbose and explicitly state when a
device<->driver match was rejected by the probe-function of the driver.
Now all code-paths report what is currently happening which helps
debugging, because you don't have to remember that no printout means
the match is rejected (and then you still don't know if it was because
of ENODEV or ENXIO).
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits)
debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning
sysfs: remove "last sysfs file:" line from the oops messages
drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"
memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION
SYSFS: Fix erroneous comments for sysfs_update_group().
driver core: remove the driver-model structures from the documentation
driver core: Add the device driver-model structures to kerneldoc
Translated Documentation/email-clients.txt
RAW driver: Remove call to kobject_put().
reboot: disable usermodehelper to prevent fs access
efivars: prevent oops on unload when efi is not enabled
Allow setting of number of raw devices as a module parameter
Introduce CONFIG_GOOGLE_FIRMWARE
driver: Google Memory Console
driver: Google EFI SMI
x86: Better comments for get_bios_ebda()
x86: get_bios_ebda_length()
misc: fix ti-st build issues
params.c: Use new strtobool function to process boolean inputs
debugfs: move to new strtobool
...
Fix up trivial conflicts in fs/debugfs/file.c due to the same patch
being applied twice, and an unrelated cleanup nearby.
The driver core tries to prevent race conditions between runtime PM
and driver removal from happening by incrementing the runtime PM
usage counter of the device and executing pm_runtime_barrier() before
running the bus notifier and the ->remove() callbacks provided by the
device's subsystem or driver. This guarantees that, if a future
runtime suspend of the device has been scheduled or a runtime resume
or idle request has been queued up right before the driver removal,
it will be canceled or waited for to complete and no other
asynchronous runtime suspend or idle requests for the device will be
put into the PM workqueue until the ->remove() callback returns.
However, it doesn't prevent resume requests from being queued up
after pm_runtime_barrier() has been called and it doesn't prevent
pm_runtime_resume() from executing the device subsystem's runtime
resume callback. Morever, it prevents the device's subsystem or
driver from putting the device into the suspended state by calling
pm_runtime_suspend() from its ->remove() routine. This turns out to
be a major inconvenience for some subsystems and drivers that want to
leave the devices they handle in the suspended state.
To really prevent runtime PM callbacks from racing with the bus
notifier callback in __device_release_driver(), which is necessary,
because the notifier is used by some subsystems to carry out
operations affecting the runtime PM functionality, use
pm_runtime_get_sync() instead of the combination of
pm_runtime_get_noresume() and pm_runtime_barrier(). This will resume
the device if it's in the suspended state and will prevent it from
being suspended again until pm_runtime_put_*() is called.
To allow subsystems and drivers to put devices into the suspended
state by calling pm_runtime_suspend() from their ->remove() routines,
execute pm_runtime_put_sync() after running the bus notifier in
__device_release_driver(). This will require subsystems and drivers
to make their ->remove() callbacks avoid races with runtime PM
directly, but it will allow of more flexibility in the handling of
devices during the removal of their drivers.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Before commit
b402843 (Driver core: move dev_get/set_drvdata to drivers/base/dd.c)
calling dev_set_drvdata with dev=NULL was an unchecked error. After some
discussion about what to return in this case removing the check (and so
producing a null pointer exception) seems fine.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a device is registered to a bus it will be a) added to the list
of devices of the bus and b) bind to a driver (if one matches). As a
result of a driver being registered at this bus between a) and b) this
device could already be bound to a driver. This leads to a warning
and incorrect refcounting.
To fix this add a check to device_attach to identify an already bound
device.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add BUS_NOTIFY_BIND_DRIVER as a bus notifier event.
For driver binding/unbinding we with this in
place have the following bus notifier events:
- BUS_NOTIFY_BIND_DRIVER - before ->probe()
- BUS_NOTIFY_BOUND_DRIVER - after ->probe()
- BUS_NOTIFY_UNBIND_DRIVER - before ->remove()
- BUS_NOTIFY_UNBOUND_DRIVER - after ->remove()
The event BUS_NOTIFY_BIND_DRIVER allows bus code
to be notified that ->probe() is about to be called.
Useful for bus code that needs to setup hardware before
the driver gets to run. With this in place platform
drivers can be loaded and unloaded as modules and the
new BIND event allows bus code to control for instance
device clocks that must be enabled before the driver
can be executed.
Without this patch there is no way for the bus code to
get notified that a modular driver is about to be probed.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fix a potential race condition in the driver_bound() function
in the file driver/base/dd.c.
The broadcast of the BUS_NOTIFY_BOUND_DRIVER notifier should be done
after adding the new device to the driver list. Otherwise notifier
listener will fail if they use functions like usb_find_interface().
The patch is against kernel 2.6.33. Please merge it.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In the future, we are going to be changing the lock type for struct
device (once we get the lockdep infrastructure properly worked out) To
make that changeover easier, and to possibly burry the lock in a
different part of struct device, let's create some functions to lock and
unlock a device so that no out-of-core code needs to be changed in the
future.
This patch creates the device_lock/unlock/trylock() functions, and
converts all in-tree users to them.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Magnus Damm <damm@igel.co.jp>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Alex Chiang <achiang@hp.com>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Yu Zhao <yu.zhao@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: CHENG Renquan <rqcheng@smu.edu.sg>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Frans Pop <elendil@planet.nl>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No one should directly access the driver_data field, so remove the field
and make it private. We dynamically create the private field now if it
is needed, to handle drivers that call get/set before they are
registered with the driver core.
Also update the copyright notices on these files while we are there.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Introduce a core framework for run-time power management of I/O
devices. Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level. Document all these things.
Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@igel.co.jp>
This patch adds a new bus notifier event which is emitted _after_ a
device is removed from its driver. This event will be used by the
dma-api debug code to check if a driver has released all dma allocations
for that device.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.
Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)
This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes 100ms polling for driver_probe_done in
wait_for_device_probe(), and uses wait_event() instead.
Removing polling in fs initialization may lead to
a faster boot.
This patch also changes the return type of wait_for_device_done()
from int to void.
This patch is against Arjan's patch in linux-next tree.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves bus->match out from driver_probe_device and
does not hold device lock to check the match between a device
and a driver.
The idea has been verified by the commit 6cd4958609,
which leads to a faster boot. But the commit 6cd4958609 has
the following drawbacks: 1),only does the quick check in
the path of __driver_attach->driver_probe_device, not in other
paths; 2),for a matched device and driver, check the same match
twice. It is a waste of cpu ,especially for some drivers with long
device id table (eg. usb-storage driver).
This patch adds a helper of driver_match_device to check the match
in all paths, and testes the match only once.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
there's a few places that currently loop over driver_probe_done(), and
I'm about to add another one. This patch abstracts it into a helper
to reduce duplication.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 93e746db18.
Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In __device_release_driver(),driver_sysfs_remove() has removed the
driver link under device dir in sysfs, but sysfs_remove_link() is
called again to do such thing. Remove the duplicate call to
sys_remove_link().
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds a quick check for the driver<->device match before
taking the locks and doin gthe expensive checks. Taking the lock hurts
in asynchronous boot context where the device lock gets hit; one of the
init functions takes the lock and goes to do an expensive hardware init;
the other init functions walk the same PCI list and get stuck on the
lock as a result.
For the common case, we can know there's no chance whatsoever of a match
if the device isn't in the drivers ID table... so this patch does that
check as a best-effort-avoid-the-lock approach.
Bootcharts for before and after can be seen at
http://www.fenrus.org/before.svghttp://www.fenrus.org/after.svg
Note the long time "agp_ali_init" takes in the first graph; my laptop
doesn't even have an ALI chip in it! (the bootgraphs look a bit
dissimilar, but that's the point, the first one has a bunch of arbitrary
delays in it that cause it to look very different)
This reduces my kernel boot time by about 20%
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix up a number of coding style issues in the drivers/base/ directory
that have annoyed me over the years. checkpatch.pl is now very happy.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1013) was suggested by David Woodhouse; it fixes a race
in the driver core. If a device is unregistered at the same time as
its driver is unloaded, the driver's code pages may be unmapped while
the remove method is still running. The calls to get_driver() and
put_driver() were intended to prevent this, but they don't work if the
driver's module count has already dropped to 0.
Instead, the patch keeps the device on the driver's list until after
the remove method has returned. This forces the necessary
synchronization to occur.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The driver core debugging messages are a mess. This provides a unified
message that makes them actually useful.
The format for new kobject debug messages should be:
driver/bus/class: 'OBJECT_NAME': FUNCTION_NAME: message.\n
Note, the class code is not changed in this patch due to pending patches
in my queue that this would conflict with. A later patch will clean
them up.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only. Now drivers can be
safely create on the stack or statically (like they currently are.)
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
struct bus_type is static everywhere in the kernel. This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure. This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.
Thanks to Kay for the build fixes on this patch.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
CC drivers/base/dd.o
drivers/base/dd.c:211: warning: =E2=80=98device_probe_drivers=E2=80=99 defi=
ned but not used
Looks like the following is dead.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the PCI_MULTITHREAD_PROBE option that had already
been marked as broken.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't fail bus_attach_device() if the device cannot be bound.
If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device. As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().
Also remove an unneeded check in bus_rescan_devices_helper().
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make multithreaded probing work per subsystem instead of per driver.
It doesn't make much sense to probe the same device for multiple drivers in
parallel (after all, only one driver can bind to the device). Instead, create
a probing thread for each device that probes the drivers one after another.
Also make the decision to use multi-threaded probe per bus instead of per
device and adapt the pci code.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement device resource management, in short, devres. A device
driver can allocate arbirary size of devres data which is associated
with a release function. On driver detach, release function is
invoked on the devres data, then, devres data is freed.
devreses are typed by associated release functions. Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function. Both usages are
supported.
devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).
This patch adds devres core including documentation and the following
managed interfaces.
* alloc/free : devm_kzalloc(), devm_kzfree()
* IO region : devm_request_region(), devm_release_region()
* IRQ : devm_request_irq(), devm_free_irq()
* DMA : dmam_alloc_coherent(), dmam_free_coherent(),
dmam_declare_coherent_memory(), dmam_pool_create(),
dmam_pool_destroy()
* PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
pcim_iomap(), pcim_iounmap()
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Change function call order in device_bind_driver().
If we create symlinks (which might fail) before adding the device to the list
we don't have to clean up afterwards (which we didn't).
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't stop on the first ->probe error that is not -ENODEV/-ENXIO.
There might be a driver registered returning an unresonable return code, and
this stops probing completely even though it may make sense to try the next
possible driver. At worst, we may end up with an unbound device.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Create the "driver" link before the child device may be created by
the probing logic. This makes it possible for userspace (udev), to
determine the driver property of the parent device, at the time the
child device is created.
Signed-off-by: Kay Sievers <kay.sievers@novell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I finally did as you suggested and added the notifier to the struct
bus_type itself. There are still problems to be expected is something
attaches to a bus type where the code can hook in different struct
device sub-classes (which is imho a big bogosity but I won't even try to
argue that case now) but it will solve nicely a number of issues I've
had so far.
That also means that clients interested in registering for such
notifications have to do it before devices are added and after bus types
are registered. Fortunately, most bus types that matter for the various
usage scenarios I have in mind are registerd at postcore_initcall time,
which means I have a really nice spot at arch_initcall time to add my
notifiers.
There are 4 notifications provided. Device being added (before hooked to
the bus) and removed (failure of previous case or after being unhooked
from the bus), along with driver being bound to a device and about to be
unbound.
The usage I have for these are:
- The 2 first ones are used to maintain a struct device_ext that is
hooked to struct device.firmware_data. This structure contains for now a
pointer to the Open Firmware node related to the device (if any), the
NUMA node ID (for quick access to it) and the DMA operations pointers &
iommu table instance for DMA to/from this device. For bus types I own
(like IBM VIO or EBUS), I just maintain that structure directly from the
bus code when creating the devices. But for bus types managed by generic
code like PCI or platform (actually, of_platform which is a variation of
platform linked to Open Firmware device-tree), I need this notifier.
- The other two ones have a completely different usage scenario. I have
cases where multiple devices and their drivers depend on each other. For
example, the IBM EMAC network driver needs to attach to a MAL DMA engine
which is a separate device, and a PHY interface which is also a separate
device. They are all of_platform_device's (well, about to be with my
upcoming patches) but there is no say in what precise order the core
will "probe" them and instanciate the various modules. The solution I
found for that is to have the drivers for emac to use multithread_probe,
and wait for a driver to be bound to the target MAL and PHY control
devices (the device-tree contains reference to the MAL and PHY interface
nodes, which I can then match to of_platform_devices). Right now, I've
been polling, but with that notifier, I can more cleanly wait (with a
timeout of course).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The multithreaded-probing code has a problem: after one initcall level (eg,
core_initcall) has been processed, we will then start processing the next
level (postcore_initcall) while the kernel threads which are handling
core_initcall are still executing. This breaks the guarantees which the
layered initcalls previously gave us.
IOW, we want to be multithreaded _within_ an initcall level, but not between
different levels.
Fix that up by causing the probing code to wait for all outstanding probes at
one level to complete before we start processing the next level.
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sure data is freed if the kthread fails to start.
Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a potential deadlock in the driver core. It boils down to
the fact that bus_remove_device() calls klist_remove() instead of
klist_del(), thereby waiting until the reference count of the
klist_node in the bus's klist of devices drops to 0. The refcount
can't reach 0 so long as a modprobe process is trying to bind a new
driver to the device being removed, by calling __driver_attach(). The
problem is that __driver_attach() tries to acquire the device's
parent's semaphore, but the caller of bus_remove_device() is quite
likely to own that semaphore already.
It isn't sufficient just to replace klist_remove() with klist_del().
Doing so runs the risk that the device would remain on the bus's klist
of devices for some time, and so could be bound to another driver even
after it was unregistered. What's needed is a new way to distinguish
whether or not a device is registered, based on a criterion other than
whether its klist_node is linked into the bus's klist of devices. That
way driver binding can fail when the device is unregistered, even if
it is still linked into the klist.
This patch (as782) implements the solution, by adding a new bitflag to
indiate when a struct device is registered, by testing the flag before
allowing a driver to bind a device, and by changing the definition of
the device_is_registered() inline.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds the infrastructure for drivers to do a threaded probe, and
waits at init time for all currently outstanding probes to complete.
A new kernel thread will be created when the probe() function for the
driver is called, if the multithread_probe bit is set in the driver
saying it can support this kind of operation.
I have tested this with USB and PCI, and it works, and shaves off a lot
of time in the boot process, but there are issues with finding root boot
disks, and some USB drivers assume that this can never happen, so it is
currently not enabled for any bus type. Individual drivers can enable
this right now if they wish, and bus authors can selectivly turn it on
as well, once they determine that their subsystem will work properly
with it.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as667) changes the __device_release_driver() routine to
prevent it from crashing when it runs across a device not on any bus.
This seems logical, inasmuch as the corresponding bus_add_device()
routine has an explicit check allowing it to accept such devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add bus_type probe, remove and shutdown methods to replace the
corresponding methods in struct device_driver. This matches
the way we handle the suspend/resume methods.
Since the bus methods override the device_driver methods, warn
if a device driver is registered whose methods will not be
called.
The long-term idea is to remove the device_driver methods entirely.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as604) makes the driver core hold a device's parent's lock
as well as the device's lock during calls to the probe and remove
methods in a driver. This facility is needed by USB device drivers,
owing to the peculiar way USB devices work:
A device provides multiple interfaces, and drivers are bound
to interfaces rather than to devices;
Nevertheless a reset, reset-configuration, suspend, or resume
affects the entire device and requires the caller to hold the
lock for the device, not just a lock for one of the interfaces.
Since a USB driver's probe method is always called with the interface
lock held, the locking order rules (always lock parent before child)
prevent these methods from acquiring the device lock. The solution
provided here is to call all probe and remove methods, for all devices
(not just USB), with the parent lock already acquired.
Although currently only the USB subsystem requires these changes, people
have mentioned in prior discussion that the overhead of acquiring an
extra semaphore in all the prove/remove sequences is not overly large.
Up to now, the USB core has been using its own set of private
semaphores. A followup patch will remove them, relying entirely on the
device semaphores provided by the driver core.
The code paths affected by this patch are:
device_add and device_del: The USB core already holds the parent
lock, so no actual change is needed.
driver_register and driver_unregister: The driver core will now
lock both the parent and the device before probing or removing.
driver_bind and driver_unbind (in sysfs): These routines will
now lock both the parent and the device before binding or
unbinding.
bus_rescan_devices: The helper routine will lock the parent
before probing a device.
I have not tested this patch for conflicts with other subsystems. As
far as I can see, the only possibility of conflict would lie in the
bus_rescan_devices pathway, and it seems pretty remote. Nevertheless,
it would be good for this to get a lot of testing in -mm.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as603) makes a few small fixes to the driver core:
Change spin_lock_irq for a klist lock to spin_lock;
Fix reference count leaks;
Minor spelling and formatting changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
bus_rescan_devices_helper() does not hold the dev->sem when it checks for
!dev->driver(). device_attach() holds the sem, but calls again
device_bind_driver() even when dev->driver is set.
What happens is that a first device_attach() call (module insertion time)
is on the way binding the device to a driver. Another thread calls
bus_rescan_devices(). Now when bus_rescan_devices_helper() checks for
dev->driver it is still NULL 'cos the the prior device_attach() is not yet
finished. But as soon as the first one releases the dev->sem the second
device_attach() tries to rebind the already bound device again.
device_bind_driver() does this blindly which leads to a corrupt
driver->klist_devices list (the device links itself, the head points to the
device). Later a call to device_release_driver() sets dev->driver to NULL
and breaks the link it has to itself on knode_driver. Rmmoding the driver
later calls driver_detach() which leads to an endless loop 'cos the list
head in klist_devices still points to the device. And since dev->driver is
NULL it's stuck with the same device forever. Boom. And rmmod hangs.
Very easy to reproduce with new-style pcmcia and a 16bit card. Just loop
modprobe <pcmcia-modules> ;cardctl eject; rmmod <card driver, pcmcia
modules>.
Easiest fix is to check if the device is already bound to a driver in
device_bind_driver(). This avoids the double binding.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
at the moment, the list_head semantics are
list_add(node, head)
whereas current klist semantics are
klist_add(head, node)
This is bound to cause confusion, and since klist is the newcomer, it
should follow the list_head semantics.
I also added missing include guards to klist.h
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds a single file, "bind", to the sysfs directory of every driver
registered with the driver core. To bind a device to a driver, write
the bus id of the device you wish to bind to that specific driver to the
"bind" file (remember to not add a trailing \n). If that bus id matches
a device on that bus, and it does not currently have a driver bound to
it, the probe sequence will be initiated with that driver and device.
Note, this requires that the driver itself be willing and able to accept
that device (usually through a device id type table). This patch does
not make it possible to override the driver's id table.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The error handling in bus_add_device() and device_attach() is simply
non-existing. This patch propagates any error from device_attach to
the upper layers to allow for a proper recovery.
From: Hannes Reinecke <hare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch is intended for your "driver" tree. It fixes several subtle
races in driver_detach() and device_release_driver() in the driver-model
core.
The major change is to use klist_remove() rather than klist_del() when
taking a device off its driver's list. There's no other way to guarantee
that the list pointers will be updated before some other driver binds to
the device. For this to work driver_detach() can't use a klist iterator,
so the loop over the devices must be written out in full. In addition the
patch protects against the possibility that, when a driver and a device
are unregistered at the same time, one may be unloaded from memory before
the other is finished using it.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There's no check to see if the device is already bound to a driver, which
could do bad things. The first thing to go wrong is that it will try to match
a driver with a device already bound to one. In some cases (it appears with
USB with drivers/usb/core/usb.c::usb_match_id()), some drivers will match a
device based on the class type, so it would be common (especially for HID
devices) to match a device that is already bound.
The fun comes when ->probe() is called, it fails, then
driver_probe_device() does this:
dev->driver = NULL;
Later on, that pointer could be be dereferenced without checking and cause
hell to break loose.
This problem could be nasty. It's very hardware dependent, since some
devices could have a different set of matching qualifiers than others.
Now, I don't quite see exactly where/how you were getting that crash.
You're dereferencing bad memory, but I'm not sure which pointer was bad
and where it came from, but it could have come from a couple of different
places.
The patch below will hopefully fix it all up for you. It's against
2.6.12-rc2-mm1, and does the following:
- Move logic to driver_probe_device() and comments uncommon returns:
1 - If device is bound
0 - If device not bound, and no error
error - If there was an error.
- Move locking to caller of that function, since we want to lock a
device for the entire time we're trying to bind it to a driver (to
prevent against a driver being loaded at the same time).
- Update __device_attach() and __driver_attach() to do that locking.
- Check if device is already bound in __driver_attach()
- Update the converse device_release_driver() so it locks the device
around all of the operations.
- Mark driver_probe_device() as static and remove export. It's an
internal function, it should stay that way, and there are no other
callers. If there is ever a need to export it, we can audit it as
necessary.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Tomeu Vizoso
