Here are 2 small fixes for some driver core issues that have been
reported. There is also a kernfs "fix" here, which was then reverted
because it was found to cause problems in linux-next.
The driver core fixes both resolve reported issues, one with gpioint
stuff that showed up in 5.3-rc1, and the other finally (and hopefully)
resolves a very long standing race when removing glue directories. It's
nice to get that issue finally resolved and the developers involved
should be applauded for the persistence it took to get this patch
finally accepted.
All of these have been in linux-next for a while with no reported
issues. Well, the one reported issue, hence the revert :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are two small fixes for some driver core issues that have been
reported. There is also a kernfs "fix" here, which was then reverted
because it was found to cause problems in linux-next.
The driver core fixes both resolve reported issues, one with gpioint
stuff that showed up in 5.3-rc1, and the other finally (and hopefully)
resolves a very long standing race when removing glue directories.
It's nice to get that issue finally resolved and the developers
involved should be applauded for the persistence it took to get this
patch finally accepted.
All of these have been in linux-next for a while with no reported
issues. Well, the one reported issue, hence the revert :)"
* tag 'driver-core-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Revert "kernfs: fix memleak in kernel_ops_readdir()"
kernfs: fix memleak in kernel_ops_readdir()
driver core: Fix use-after-free and double free on glue directory
driver core: platform: return -ENXIO for missing GpioInt
There is a race condition between removing glue directory and adding a new
device under the glue dir. It can be reproduced in following test:
CPU1: CPU2:
device_add()
get_device_parent()
class_dir_create_and_add()
kobject_add_internal()
create_dir() // create glue_dir
device_add()
get_device_parent()
kobject_get() // get glue_dir
device_del()
cleanup_glue_dir()
kobject_del(glue_dir)
kobject_add()
kobject_add_internal()
create_dir() // in glue_dir
sysfs_create_dir_ns()
kernfs_create_dir_ns(sd)
sysfs_remove_dir() // glue_dir->sd=NULL
sysfs_put() // free glue_dir->sd
// sd is freed
kernfs_new_node(sd)
kernfs_get(glue_dir)
kernfs_add_one()
kernfs_put()
Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.
In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.
The following calltrace is captured in kernel 4.14 with the following patch
applied:
commit 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")
--------------------------------------------------------------------------
[ 3.633703] WARNING: CPU: 4 PID: 513 at .../fs/kernfs/dir.c:494
Here is WARN_ON(!atomic_read(&kn->count) in kernfs_get().
....
[ 3.633986] Call trace:
[ 3.633991] kernfs_create_dir_ns+0xa8/0xb0
[ 3.633994] sysfs_create_dir_ns+0x54/0xe8
[ 3.634001] kobject_add_internal+0x22c/0x3f0
[ 3.634005] kobject_add+0xe4/0x118
[ 3.634011] device_add+0x200/0x870
[ 3.634017] _request_firmware+0x958/0xc38
[ 3.634020] request_firmware_into_buf+0x4c/0x70
....
[ 3.634064] kernel BUG at .../mm/slub.c:294!
Here is BUG_ON(object == fp) in set_freepointer().
....
[ 3.634346] Call trace:
[ 3.634351] kmem_cache_free+0x504/0x6b8
[ 3.634355] kernfs_put+0x14c/0x1d8
[ 3.634359] kernfs_create_dir_ns+0x88/0xb0
[ 3.634362] sysfs_create_dir_ns+0x54/0xe8
[ 3.634366] kobject_add_internal+0x22c/0x3f0
[ 3.634370] kobject_add+0xe4/0x118
[ 3.634374] device_add+0x200/0x870
[ 3.634378] _request_firmware+0x958/0xc38
[ 3.634381] request_firmware_into_buf+0x4c/0x70
--------------------------------------------------------------------------
Fixes: 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")
Signed-off-by: Muchun Song <smuchun@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Link: https://lore.kernel.org/r/20190727032122.24639-1-smuchun@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Fix duplicate device_unregister() calls (multiple threads competing to
do unregister work when scheduling device removal from a sysfs attribute
of the self-same device).
- Fix badblocks registration order bug. Ensure region badblocks are
initialized in advance of namespace registration.
- Fix a deadlock between the bus lock and probe operations.
- Export device-core infrastructure to coordinate async operations via
the device ->dead state.
- Add device-core infrastructure to validate device_lock() usage with
lockdep.
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Merge tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
"A collection of locking and async operations fixes for v5.3-rc2. These
had been soaking in a branch targeting the merge window, but missed
due to a regression hunt. This fixed up version has otherwise been in
-next this past week with no reported issues.
In order to gain confidence in the locking changes the pull also
includes a debug / instrumentation patch to enable lockdep coverage
for libnvdimm subsystem operations that depend on the device_lock for
exclusion. As mentioned in the changelog it is a hack, but it works
and documents the locking expectations of the sub-system in a way that
others can use lockdep to verify. The driver core touches got an ack
from Greg.
Summary:
- Fix duplicate device_unregister() calls (multiple threads competing
to do unregister work when scheduling device removal from a sysfs
attribute of the self-same device).
- Fix badblocks registration order bug. Ensure region badblocks are
initialized in advance of namespace registration.
- Fix a deadlock between the bus lock and probe operations.
- Export device-core infrastructure to coordinate async operations
via the device ->dead state.
- Add device-core infrastructure to validate device_lock() usage with
lockdep"
* tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
driver-core, libnvdimm: Let device subsystems add local lockdep coverage
libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock
libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()
libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant
libnvdimm/region: Register badblocks before namespaces
libnvdimm/bus: Prevent duplicate device_unregister() calls
drivers/base: Introduce kill_device()
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.
A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.
Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:
"Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
using it as much as anything else, so user beware :)
I don't object to it if it makes things easier for you to debug."
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
The libnvdimm subsystem arranges for devices to be destroyed as a result
of a sysfs operation. Since device_unregister() cannot be called from
an actively running sysfs attribute of the same device libnvdimm
arranges for device_unregister() to be performed in an out-of-line async
context.
The driver core maintains a 'dead' state for coordinating its own racing
async registration / de-registration requests. Rather than add local
'dead' state tracking infrastructure to libnvdimm device objects, export
the existing state tracking via a new kill_device() helper.
The kill_device() helper simply marks the device as dead, i.e. that it
is on its way to device_del(), or returns that the device was already
dead. This can be used in advance of calling device_unregister() for
subsystems like libnvdimm that might need to handle multiple user
threads racing to delete a device.
This refactoring does not change any behavior, but it is a pre-requisite
for follow-on fixes and therefore marked for -stable.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Fixes: 4d88a97aa9 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver...")
Cc: <stable@vger.kernel.org>
Tested-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/156341207332.292348.14959761496009347574.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups. Because of this, there is going
to be some merge issues with your tree at the moment, I'll follow up
with the expected resolutions to make it easier for you.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups (will cause build warnings
with s390 and coresight drivers in your tree)
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse
easier due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of merge
issues that Stephen has been patient with me for. Other than the merge
issues, functionality is working properly in linux-next :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
Add a helper to match device by the of_node. This will be later used
to provide wrappers to the device iterators for {bus/class/driver}_find_device().
Convert other users to reuse this new helper.
Cc: Alan Tull <atull@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: devicetree@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-fpga@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It looks like the child device is often matched with a name.
This introduces a helper that does it automatically.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is not absolutely clear from the docs how the cleanup path after
device_add() should look like so spell it out explicitly.
No functional changes, just documentation.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 4c06c4e6cf ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called. In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".
For this reason, partially revert commit 4c06c4e6cf as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former. [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]
This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.
Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.
Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.
To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it. Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).
Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).
Fixes: e2f3cd831a ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the
driver core to probe for a consumer driver automatically after binding
a driver to the supplier device on a persistent managed device link.
As unbinding the supplier driver on a managed device link causes the
consumer driver to be detached from its device automatically, this
flag provides a complementary mechanism which is needed to address
some "composite device" use cases.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Even though stateful device links are managed by the driver core in
principle, their creators are allowed and sometimes even expected
to drop references to them via device_link_del() or
device_link_remove(), but that doesn't really play well with the
"persistent" link concept.
If "persistent" managed device links are created from driver
probe callbacks, device_link_add() called to do that will take a
new reference on the link each time the callback runs and those
references will never be dropped, which kind of isn't nice.
This issues arises because of the link reference counting carried
out by device_link_add() for existing links, but that is only done to
avoid deleting device links that may still be necessary, which
shouldn't be a concern for managed (stateful) links. These device
links are managed by the driver core and whoever creates one of them
will need it at least as long as until the consumer driver is detached
from its device and deleting it may be left to the driver core just
fine.
For this reason, rework device_link_add() to apply the reference
counting to stateless links only and make device_link_del() and
device_link_remove() drop references to stateless links only too.
After this change, if called to add a stateful device link for
a consumer-supplier pair for which a stateful device link is
present already, device_link_add() will return the existing link
without incrementing its reference counter. Accordingly,
device_link_del() and device_link_remove() will WARN() and do
nothing when called to drop a reference to a stateful link. Thus,
effectively, all stateful device links will be owned by the driver
core.
In addition, clean up the handling of the link management flags,
DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER, so that
(a) they are never set at the same time and (b) if device_link_add()
is called for a consumer-supplier pair with an existing stateful link
between them, the flags of that link will be combined with the flags
passed to device_link_add() to ensure that the life time of the link
is sufficient for all of the callers of device_link_add() for the
same consumer-supplier pair.
Update the device_link_add() kerneldoc comment to reflect the
above changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
as it affects all suppliers of the consumer device and not just the
one pointed to by the device link being dropped. Worst case it may
cause the consumer device to stop working unexpectedly. Moreover, in
principle it is racy with respect to runtime PM of the consumer
device.
To avoid these problems drop runtime PM references on the particular
supplier pointed to by the link in question only and do that after
the link has been dropped from the consumer device's list of links to
suppliers, which is in device_link_free().
Fixes: a0504aecba ("PM / runtime: Drop usage count for suppliers at device link removal")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, it is not valid to add a device link from a consumer
driver ->probe callback to a supplier that is still probing too, but
generally this is a valid use case. For example, if the consumer has
just acquired a resource that can only be available if the supplier
is functional, adding a device link to that supplier right away
should be safe (and even desirable arguably), but device_link_add()
doesn't handle that case correctly and the initial state of the link
created by it is wrong then.
To address this problem, change the initial state of device links
added between a probing supplier and a probing consumer to
DL_STATE_CONSUMER_PROBE and update device_links_driver_bound() to
skip such links on the supplier side.
With this change, if the supplier probe completes first,
device_links_driver_bound() called for it will skip the link state
update and when it is called for the consumer, the link state will
be updated to "active". In turn, if the consumer probe completes
first, device_links_driver_bound() called for it will change the
state of the link to "active" and when it is called for the
supplier, the link status update will be skipped.
However, in principle the supplier or consumer probe may still fail
after the link has been added, so modify device_links_no_driver() to
change device links in the "active" or "consumer probe" state to
"dormant" on the supplier side and update __device_links_no_driver()
to change the link state to "available" only if it is "consumer
probe" or "active".
Then, if the supplier probe fails first, the leftover link to the
probing consumer will become "dormant" and device_links_no_driver()
called for the consumer (when its probe fails) will clean it up.
In turn, if the consumer probe fails first, it will either drop the
link, or change its state to "available" and, in the latter case,
when device_links_no_driver() is called for the supplier, it will
update the link state to "dormant". [If the supplier probe fails,
but the consumer probe succeeds, which should not happen as long as
the consumer driver is correct, the link still will be around, but
it will be "dormant" until the supplier is probed again.]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit ead18c23c2 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally without updating its flags. It is
possible, however, that the second (or any subsequent) caller of
device_link_add() for the same consumer-supplier pair will pass
DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
to it and the existing link may not behave as expected then.
First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
at all, it needs to be set like during the original initialization of
the link.
Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
(in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
updated to reflect the "active" runtime PM configuration of the
consumer-supplier pair and extra care must be taken here to avoid
possible destructive races with runtime PM of the consumer.
To that end, redefine the rpm_active field in struct device_link
as a refcount, initialize it to 1 and make rpm_resume() (for the
consumer) and device_link_add() increment it whenever they acquire
a runtime PM reference on the supplier device. Accordingly, make
rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
decrement it and drop runtime PM references to the supplier
device in a loop until rpm_active becones 1 again.
Fixes: ead18c23c2 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is incorrect to call pm_runtime_get_sync() under
device_links_write_lock(), because it may end up trying to take
device_links_read_lock() while resuming the target device and that
will deadlock in the non-SRCU case, so avoid that by resuming the
supplier device in device_link_add() before calling
device_links_write_lock().
Fixes: 21d5c57b37 ("PM / runtime: Use device links")
Fixes: baa8809f60 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit ead18c23c2 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally. However, if the flags passed to
it on the second (or any subsequent) attempt to create a device
link between the same consumer-supplier pair are not compatible with
the existing link's flags, that is incorrect.
First off, if the existing link is stateless and the next caller of
device_link_add() for the same consumer-supplier pair wants a
stateful one, or the other way around, the existing link cannot be
returned, because it will not match the expected behavior, so make
device_link_add() dump the stack and return NULL in that case.
Moreover, if the DL_FLAG_AUTOREMOVE_CONSUMER flag is passed to
device_link_add(), its caller will expect its reference to the link
to be dropped automatically on consumer driver removal, which will
not happen if that flag is not set in the link's flags (and
analogously for DL_FLAG_AUTOREMOVE_SUPPLIER). For this reason, make
device_link_add() update the existing link's flags accordingly
before returning it to the caller.
Fixes: ead18c23c2 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change the list walk in device_links_driver_cleanup() to a safe one
to avoid use-after-free when dropping a link from the list during the
walk.
Also, while at it, fix device_link_add() to refuse to create
stateless device links with DL_FLAG_AUTOREMOVE_SUPPLIER set, which is
an invalid combination (setting that flag means that the driver core
should manage the link, so it cannot be stateless), and extend the
kerneldoc comment of device_link_add() to cover the
DL_FLAG_AUTOREMOVE_SUPPLIER flag properly too.
Fixes: 1689cac5b3 ("driver core: Add flag to autoremove device link on supplier unbind")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add an additional bit flag to the device_private struct named "dead".
This additional flag provides a guarantee that when a device_del is
executed on a given interface an async worker will not attempt to attach
the driver following the earlier device_del call. Previously this
guarantee was not present and could result in the device_del call
attempting to remove a driver from an interface only to have the async
worker attempt to probe the driver later when it finally completes the
asynchronous probe call.
One additional change added was that I pulled the check for dev->driver
out of the __device_attach_driver call and instead placed it in the
__device_attach_async_helper call. This was motivated by the fact that the
only other caller of this, __device_attach, had already taken the
device_lock() and checked for dev->driver. Instead of testing for this
twice in this path it makes more sense to just consolidate the dev->dead
and dev->driver checks together into one set of checks.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DL_FLAG_AUTOREMOVE_CONSUMER/SUPPLIER means "Remove the link
automatically on consumer/supplier driver unbind", that means we should
remove whole the device_link when there is no this driver no matter what
the ref_count of the link is.
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On platforms making a fair use of regulators, the dev_info() messages
coming from the device link function are a bit too verbose. The amount
of message will increase further with the clock framework joining the
device link party.
These messages looks valuable for people debugging device link related
issues, so dev_dbg() looks more appropriate than dev_info().
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As the description of struct device_private says, it stores data which
is private to driver core. And it already has similar fields like:
knode_parent, knode_driver, knode_driver and knode_bus. This look it is
more proper to put knode_class together with those fields to make it
private to driver core.
This patch move device->knode_class to device_private to make it comply
with code convention.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the "big" set of driver core patches for 4.21-rc1.
It's not really big, just a number of small changes for some reported
issues, some documentation updates to hopefully make it harder for
people to abuse the driver model, and some other minor cleanups.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the "big" set of driver core patches for 4.21-rc1.
It's not really big, just a number of small changes for some reported
issues, some documentation updates to hopefully make it harder for
people to abuse the driver model, and some other minor cleanups.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
mm, memory_hotplug: update a comment in unregister_memory()
component: convert to DEFINE_SHOW_ATTRIBUTE
sysfs: Disable lockdep for driver bind/unbind files
driver core: Add missing dev->bus->need_parent_lock checks
kobject: return error code if writing /sys/.../uevent fails
driver core: Move async_synchronize_full call
driver core: platform: Respect return code of platform_device_register_full()
kref/kobject: Improve documentation
drivers/base/memory.c: Use DEVICE_ATTR_RO and friends
driver core: Replace simple_strto{l,ul} by kstrtou{l,ul}
kernfs: Improve kernfs_notify() poll notification latency
kobject: Fix warnings in lib/kobject_uevent.c
kobject: drop unnecessary cast "%llu" for u64
driver core: fix comments for device_block_probing()
driver core: Replace simple_strtol by kstrtoint
Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.
With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.
Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current kref and kobject documentation may be
insufficient to understand these common pitfalls regarding
object lifetime and object releasing.
Add a bit more documentation and improve the warnings
seen by the user, pointing to the right piece of documentation.
Also, it's important to understand that making fun of people
publicly is not at all helpful, doesn't provide any value,
and it's not a healthy way of encouraging developers to do better.
"Mocking mercilessly" will, if anything, make developers feel bad
and go away. This kind of behavior should not be encouraged or justified.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The simple_strto{l,ul} are deprecated, use kstrtou{l,ul} instead.
Signed-off-by: Kaitao cheng <pilgrimtao@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Software node is a new struct fwnode_handle type that can be
used to describe devices in kernel (software). It is meant
to complement fwnodes representing real firmware nodes when
they are incomplete (for example missing device properties)
and to supply the primary fwnode when the firmware lacks
hardware description for a device completely.
The software node type is really meant to replace the
currently used "property_set" struct fwnode_handle type. The
handling of struct property_set is glued to the generic
device property handling code, and it is not possible to
create a struct property_set independently from the device
that it is bind to. struct property_set is only created when
device properties are added to already initialized struct
device, and control of it is only possible from the generic
property handling code.
Software nodes are instead designed to be created
independently from the device entries (struct device). It
makes them much more flexible, as then the device meant to
be bind to the node can be created at a later time, and from
another location. It is also possible to bind multiple
devices to a single software node if needed.
The software node implementation also includes support for
node hierarchy, which was the main motivation for this
commit. The node hierarchy was something that was requested
for the struct property_set, but it did not seem reasonable
to try to extend the property_set support for that purpose.
struct property_set was really meant only for device
property handling like the name suggests.
Support for struct property_set is not yet removed in this
commit, but it will be in the following one.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Instead of relying on the "platform_notify" callback hook,
introducing separate notification function
acpi_platform_notify() and calling that directly from
drivers core when device entries are added and removed.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since it should be possible to support several hardware
description models at the same time (at least in theory),
for example ACPI and devicetree on a running system, the
platform notifications need to be handled differently.
For now a single "platform_notify" callback function was
used to notify the underlying base system which is in charge
of the hardware description when a new device entry was
added to the system, but that callback is available to only
a single base system at the time. This will add a function
device_platform_notify() and replace all direct
platform_notify() calls with it.
device_platform_notify() will first simply call the
platform_notify() callback, so this commit has no functional
affect, however, the idea is that individual base systems
will put their direct notification calls there instead of
using the platform_notify function pointer.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here are all of the driver core and related patches for 4.19-rc1.
Nothing huge here, just a number of small cleanups and the ability to
now stop the deferred probing after init happens.
All of these have been in linux-next for a while with only a merge issue
reported. That merge issue is in fs/sysfs/group.c and Stephen has
posted the diff of what it should be to resolve this. I'll follow up
with that diff to this pull request.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here are all of the driver core and related patches for 4.19-rc1.
Nothing huge here, just a number of small cleanups and the ability to
now stop the deferred probing after init happens.
All of these have been in linux-next for a while with only a merge
issue reported"
* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
base: core: Remove WARN_ON from link dependencies check
drivers/base: stop new probing during shutdown
drivers: core: Remove glue dirs from sysfs earlier
driver core: remove unnecessary function extern declare
sysfs.h: fix non-kernel-doc comment
PM / Domains: Stop deferring probe at the end of initcall
iommu: Remove IOMMU_OF_DECLARE
iommu: Stop deferring probe at end of initcalls
pinctrl: Support stopping deferred probe after initcalls
dt-bindings: pinctrl: add a 'pinctrl-use-default' property
driver core: allow stopping deferred probe after init
driver core: add a debugfs entry to show deferred devices
sysfs: Fix internal_create_group() for named group updates
base: fix order of OF initialization
linux/device.h: fix kernel-doc notation warning
Documentation: update firmware loader fallback reference
kobject: Replace strncpy with memcpy
drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
kernfs: Replace strncpy with memcpy
device: Add #define dev_fmt similar to #define pr_fmt
...
Pull networking updates from David Miller:
"Highlights:
- Gustavo A. R. Silva keeps working on the implicit switch fallthru
changes.
- Support 802.11ax High-Efficiency wireless in cfg80211 et al, From
Luca Coelho.
- Re-enable ASPM in r8169, from Kai-Heng Feng.
- Add virtual XFRM interfaces, which avoids all of the limitations of
existing IPSEC tunnels. From Steffen Klassert.
- Convert GRO over to use a hash table, so that when we have many
flows active we don't traverse a long list during accumluation.
- Many new self tests for routing, TC, tunnels, etc. Too many
contributors to mention them all, but I'm really happy to keep
seeing this stuff.
- Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu.
- Lots of cleanups and fixes in L2TP code from Guillaume Nault.
- Add IPSEC offload support to netdevsim, from Shannon Nelson.
- Add support for slotting with non-uniform distribution to netem
packet scheduler, from Yousuk Seung.
- Add UDP GSO support to mlx5e, from Boris Pismenny.
- Support offloading of Team LAG in NFP, from John Hurley.
- Allow to configure TX queue selection based upon RX queue, from
Amritha Nambiar.
- Support ethtool ring size configuration in aquantia, from Anton
Mikaev.
- Support DSCP and flowlabel per-transport in SCTP, from Xin Long.
- Support list based batching and stack traversal of SKBs, this is
very exciting work. From Edward Cree.
- Busyloop optimizations in vhost_net, from Toshiaki Makita.
- Introduce the ETF qdisc, which allows time based transmissions. IGB
can offload this in hardware. From Vinicius Costa Gomes.
- Add parameter support to devlink, from Moshe Shemesh.
- Several multiplication and division optimizations for BPF JIT in
nfp driver, from Jiong Wang.
- Lots of prepatory work to make more of the packet scheduler layer
lockless, when possible, from Vlad Buslov.
- Add ACK filter and NAT awareness to sch_cake packet scheduler, from
Toke Høiland-Jørgensen.
- Support regions and region snapshots in devlink, from Alex Vesker.
- Allow to attach XDP programs to both HW and SW at the same time on
a given device, with initial support in nfp. From Jakub Kicinski.
- Add TLS RX offload and support in mlx5, from Ilya Lesokhin.
- Use PHYLIB in r8169 driver, from Heiner Kallweit.
- All sorts of changes to support Spectrum 2 in mlxsw driver, from
Ido Schimmel.
- PTP support in mv88e6xxx DSA driver, from Andrew Lunn.
- Make TCP_USER_TIMEOUT socket option more accurate, from Jon
Maxwell.
- Support for templates in packet scheduler classifier, from Jiri
Pirko.
- IPV6 support in RDS, from Ka-Cheong Poon.
- Native tproxy support in nf_tables, from Máté Eckl.
- Maintain IP fragment queue in an rbtree, but optimize properly for
in-order frags. From Peter Oskolkov.
- Improvde handling of ACKs on hole repairs, from Yuchung Cheng"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits)
bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT"
hv/netvsc: Fix NULL dereference at single queue mode fallback
net: filter: mark expected switch fall-through
xen-netfront: fix warn message as irq device name has '/'
cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0
net: dsa: mv88e6xxx: missing unlock on error path
rds: fix building with IPV6=m
inet/connection_sock: prefer _THIS_IP_ to current_text_addr
net: dsa: mv88e6xxx: bitwise vs logical bug
net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd()
ieee802154: hwsim: using right kind of iteration
net: hns3: Add vlan filter setting by ethtool command -K
net: hns3: Set tx ring' tc info when netdev is up
net: hns3: Remove tx ring BD len register in hns3_enet
net: hns3: Fix desc num set to default when setting channel
net: hns3: Fix for phy link issue when using marvell phy driver
net: hns3: Fix for information of phydev lost problem when down/up
net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero
net: hns3: Add support for serdes loopback selftest
bnxt_en: take coredump_record structure off stack
...
- Add a new framework for CPU idle time injection (Daniel Lezcano).
- Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT).
- Add support for current CPU frequency reporting to the ACPI CPPC
cpufreq driver (George Cherian).
- Rework the cooling device registration in the imx6q/thermal
driver (Bastian Stender).
- Make the pcc-cpufreq driver refuse to work with dynamic
scaling governors on systems with many CPUs to avoid
scalability issues with it (Rafael Wysocki).
- Fix the intel_pstate driver to report different maximum CPU
frequencies on systems where they really are different and to
ignore the turbo active ratio if hardware-managend P-states (HWP)
are in use; make it use the match_string() helper (Xie Yisheng,
Srinivas Pandruvada).
- Fix a minor deferred probe issue in the qcom-kryo cpufreq
driver (Niklas Cassel).
- Add a tracepoint for the tracking of frequency limits changes
(from Andriod) to the cpufreq core (Ruchi Kandoi).
- Fix a circular lock dependency between CPU hotplug and sysfs
locking in the cpufreq core reported by lockdep (Waiman Long).
- Avoid excessive error reports on driver registration failures
in the ARM cpuidle driver (Sudeep Holla).
- Add a new device links flag to the driver core to make links go
away automatically on supplier driver removal (Vivek Gautam).
- Eliminate potential race condition between system-wide power
management transitions and system shutdown (Pingfan Liu).
- Add a quirk to save NVS memory on system suspend for the ASUS
1025C laptop (Willy Tarreau).
- Make more systems use suspend-to-idle (instead of ACPI S3) by
default (Tristian Celestin).
- Get rid of stack VLA usage in the low-level hibernation code on
64-bit x86 (Kees Cook).
- Fix error handling in the hibernation core and mark an expected
fall-through switch in it (Chengguang Xu, Gustavo Silva).
- Extend the generic power domains (genpd) framework to support
attaching a device to a power domain by name (Ulf Hansson).
- Fix device reference counting and user limits initialization in
the devfreq core (Arvind Yadav, Matthias Kaehlcke).
- Fix a few issues in the rk3399_dmc devfreq driver and improve its
documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
- Drop a redundant error message from the exynos-ppmu devfreq driver
(Markus Elfring).
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Merge tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These add a new framework for CPU idle time injection, to be used by
all of the idle injection code in the kernel in the future, fix some
issues and add a number of relatively small extensions in multiple
places.
Specifics:
- Add a new framework for CPU idle time injection (Daniel Lezcano).
- Add AVS support to the armada-37xx cpufreq driver (Gregory
CLEMENT).
- Add support for current CPU frequency reporting to the ACPI CPPC
cpufreq driver (George Cherian).
- Rework the cooling device registration in the imx6q/thermal driver
(Bastian Stender).
- Make the pcc-cpufreq driver refuse to work with dynamic scaling
governors on systems with many CPUs to avoid scalability issues
with it (Rafael Wysocki).
- Fix the intel_pstate driver to report different maximum CPU
frequencies on systems where they really are different and to
ignore the turbo active ratio if hardware-managend P-states (HWP)
are in use; make it use the match_string() helper (Xie Yisheng,
Srinivas Pandruvada).
- Fix a minor deferred probe issue in the qcom-kryo cpufreq driver
(Niklas Cassel).
- Add a tracepoint for the tracking of frequency limits changes (from
Andriod) to the cpufreq core (Ruchi Kandoi).
- Fix a circular lock dependency between CPU hotplug and sysfs
locking in the cpufreq core reported by lockdep (Waiman Long).
- Avoid excessive error reports on driver registration failures in
the ARM cpuidle driver (Sudeep Holla).
- Add a new device links flag to the driver core to make links go
away automatically on supplier driver removal (Vivek Gautam).
- Eliminate potential race condition between system-wide power
management transitions and system shutdown (Pingfan Liu).
- Add a quirk to save NVS memory on system suspend for the ASUS 1025C
laptop (Willy Tarreau).
- Make more systems use suspend-to-idle (instead of ACPI S3) by
default (Tristian Celestin).
- Get rid of stack VLA usage in the low-level hibernation code on
64-bit x86 (Kees Cook).
- Fix error handling in the hibernation core and mark an expected
fall-through switch in it (Chengguang Xu, Gustavo Silva).
- Extend the generic power domains (genpd) framework to support
attaching a device to a power domain by name (Ulf Hansson).
- Fix device reference counting and user limits initialization in the
devfreq core (Arvind Yadav, Matthias Kaehlcke).
- Fix a few issues in the rk3399_dmc devfreq driver and improve its
documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
- Drop a redundant error message from the exynos-ppmu devfreq driver
(Markus Elfring)"
* tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits)
PM / reboot: Eliminate race between reboot and suspend
PM / hibernate: Mark expected switch fall-through
cpufreq: intel_pstate: Ignore turbo active ratio in HWP
cpufreq: Fix a circular lock dependency problem
cpu/hotplug: Add a cpus_read_trylock() function
x86/power/hibernate_64: Remove VLA usage
cpufreq: trace frequency limits change
cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP
cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems
cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER
cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC
cpufreq: armada-37xx: Add AVS support
dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding
PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload.
PM / devfreq: Init user limits from OPP limits, not viceversa
PM / devfreq: rk3399_dmc: fix spelling mistakes.
PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer.
dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional.
PM / devfreq: rk3399_dmc: remove wait for dcf irq event.
dt-bindings: clock: add rk3399 DDR3 standard speed bins.
...
In some cases the link between between customer and supplier
already exist, for example when a device use its parent as a supplier.
Do not warn about already existing dependencies because device_link_add()
takes care of this case.
Link: http://lkml.kernel.org/r/20180709111753eucas1p1f32e66fb2f7ea3216097cd72a132355d~-rzycA5Rg0378203782eucas1p1C@eucas1p1.samsung.com
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a race window in device_shutdown(), which may cause
-1. parent device shut down before child or
-2. no shutdown on a new probing device.
For 1st, taking the following scenario:
device_shutdown new plugin device
list_del_init(parent_dev);
spin_unlock(list_lock);
device_add(child)
probe child
shutdown parent_dev
--> now child is on the tail of devices_kset
For 2nd, taking the following scenario:
device_shutdown new plugin device
device_add(dev)
device_lock(dev);
...
device_unlock(dev);
probe dev
--> now, the new occurred dev has no opportunity to shutdown
To fix this race issue, just prevent the new probing request. With this
logic, device_shutdown() is more similar to dpm_prepare().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Plumb in get_ownership() callback for devices belonging to a class so that
they can be created with uid/gid different from global root. This will
allow network devices in a container to belong to container's root and not
global root.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For devices with a class, we create a "glue" directory between
the parent device and the new device with the class name.
This directory is never "explicitely" removed when empty however,
this is left to the implicit sysfs removal done by kobject_release()
when the object loses its last reference via kobject_put().
This is problematic because as long as it's not been removed from
sysfs, it is still present in the class kset and in sysfs directory
structure.
The presence in the class kset exposes a use after free bug fixed
by the previous patch, but the presence in sysfs means that until
the kobject is released, which can take a while (especially with
kobject debugging), any attempt at re-creating such as binding a
new device for that class/parent pair, will result in a sysfs
duplicate file name error.
This fixes it by instead doing an explicit kobject_del() when
the glue dir is empty, by keeping track of the number of
child devices of the gluedir.
This is made easy by the fact that all glue dir operations are
done with a global mutex, and there's already a function
(cleanup_glue_dir) called in all the right places taking that
mutex that can be enhanced for this. It appears that this was
in fact the intent of the function, but the implementation was
wrong.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
device_private_init is called only in core.c, extern declare is
unnecessary and make it static.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a flag to autoremove the device links on supplier driver
unbind. This obviates the need to explicitly delete the link
in the remove path.
We remove these links only when the supplier's link to its
consumers has gone to DL_STATE_SUPPLIER_UNBIND state.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Suggested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that we want to add another flag to autoremove the device link
on supplier unbind, it's fair to rename the existing flag from
DL_FLAG_AUTOREMOVE to DL_FLAG_AUTOREMOVE_CONSUMER so that we can
add similar flag for supplier later.
And, while we are touching device.h, fix a doc build warning.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a prefixing macro to dev_<level> uses similar to the pr_fmt
prefixing macro used in pr_<level> calls.
This can help avoid some string duplication in dev_<level> uses.
The default, like pr_fmt, is an empty #define dev_fmt(fmt) fmt
Rename the existing dev_<level> functions to _dev_<level> and
introduce #define dev_<level> _dev_<level> macros that use the
new #define dev_fmt
Miscellanea:
o Consistently use #defines with fmt, ... and ##__VA_ARGS__
o Remove unnecessary externs
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Device_link_remove uses the same arguments than device_link_add. The Goal
is to avoid storing the link pointer.
Signed-off-by: pascal paillet <p.paillet@st.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
If a device link is added via device_link_add() by the driver of the
link's consumer device, the supplier's runtime PM usage counter is
going to be dropped by the pm_runtime_put_suppliers() call in
driver_probe_device(). However, in that case it is not incremented
unless the supplier driver is already present and the link is not
stateless. That leads to a runtime PM usage counter imbalance for
the supplier device in a few cases.
To prevent that from happening, bump up the supplier runtime
PM usage counter in device_link_add() for all links with the
DL_FLAG_PM_RUNTIME flag set that are added at the consumer probe
time. Use pm_runtime_get_noresume() for that as the callers of
device_link_add() who want the supplier to be resumed by it are
expected to pass DL_FLAG_RPM_ACTIVE in flags to it anyway, but
additionally resume the supplier if the link is added during
consumer driver probe to retain the existing behavior for the
callers depending on it.
Fixes: 21d5c57b37 (PM / runtime: Use device links)
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here is the driver core patchset for 4.18-rc1.
The large chunk of these are firmware core documentation and api
updates. Nothing major there, just better descriptions for others to be
able to understand the firmware code better. There's also a user for a
new firmware api call.
Other than that, there are some minor updates for debugfs, kernfs, and
the driver core itself.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the driver core patchset for 4.18-rc1.
The large chunk of these are firmware core documentation and api
updates. Nothing major there, just better descriptions for others to
be able to understand the firmware code better. There's also a user
for a new firmware api call.
Other than that, there are some minor updates for debugfs, kernfs, and
the driver core itself.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
driver core: hold dev's parent lock when needed
driver-core: return EINVAL error instead of BUG_ON()
driver core: add __printf verification to device_create_groups_vargs
mm: memory_hotplug: use put_device() if device_register fail
base: core: fix typo 'can by' to 'can be'
debugfs: inode: debugfs_create_dir uses mode permission from parent
debugfs: Re-use kstrtobool_from_user()
Documentation: clarify firmware_class provenance and why we can't rename the module
Documentation: remove stale firmware API reference
Documentation: fix few typos and clarifications for the firmware loader
ath10k: re-enable the firmware fallback mechanism for testmode
ath10k: use firmware_request_nowarn() to load firmware
firmware: add firmware_request_nowarn() - load firmware without warnings
firmware_loader: make firmware_fallback_sysfs() print more useful
firmware_loader: move kconfig FW_LOADER entries to its own file
firmware_loader: replace ---help--- with help
firmware_loader: enhance Kconfig documentation over FW_LOADER
firmware_loader: document firmware_sysfs_fallback()
firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()
firmware: use () to terminate kernel-doc function names
...
__printf is useful to verify format and arguments. Remove the following
warning (with W=1):
drivers/base/core.c:2435:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
syzbot is hitting WARN() at kernfs_add_one() [1].
This is because kernfs_create_link() is confused by previous device_add()
call which continued without setting dev->kobj.parent field when
get_device_parent() failed by memory allocation fault injection.
Fix this by propagating the error from class_dir_create_and_add() to
the calllers of get_device_parent().
[1] https://syzkaller.appspot.com/bug?id=fae0fb607989ea744526d1c082a5b8de6529116f
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@syzkaller.appspotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When bridge and its endpoint is enumerated the devices are added to the
dpm list. Afterward, the bridge defers probe when IOMMU is not ready.
This causes the bridge to be moved to the end of the dpm list when
deferred probe kicks in. The order of the dpm list for bridge and
endpoint is reversed.
Add reordering code to move the bridge and its children and consumers to
the end of the pm list so the order for suspend and resume is not altered.
The code also move device and its children and consumers to the tail of
device_kset list if it is registered.
Signed-off-by: Toan Le <toanle@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If device_link_add() is invoked multiple times with the same supplier
and consumer combo, it will create the link on first addition and
return a pointer to the already existing link on all subsequent
additions.
The semantics for device_link_del() are quite different, it deletes
the link unconditionally, so multiple invocations are not allowed.
In other words, this snippet ...
struct device *dev1, *dev2;
struct device_link *link1, *link2;
link1 = device_link_add(dev1, dev2, 0);
link2 = device_link_add(dev1, dev2, 0);
device_link_del(link1);
device_link_del(link2);
... causes the following crash:
WARNING: CPU: 4 PID: 2686 at drivers/base/power/runtime.c:1611 pm_runtime_drop_link+0x40/0x50
[...]
list_del corruption, 0000000039b800a4->prev is LIST_POISON2 (00000000ecf79852)
kernel BUG at lib/list_debug.c:50!
The issue isn't as arbitrary as it may seem: Imagine a device link
which is added in both the supplier's and the consumer's ->probe hook.
The two drivers can't just call device_link_del() in their ->remove hook
without coordination.
Fix by counting multiple additions and dropping the device link only
when the last addition is unwound.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linus Torvalds