On Dell Latitude C600 laptop with Pentium 3 850MHz processor, the
speedstep-smi driver sometimes loads and sometimes doesn't load with
"change to state X failed" message.
The hardware sometimes refuses to change frequency and in this case, we
need to retry later. I found out that we need to enable interrupts while
waiting. When we enable interrupts, the hardware blockage that prevents
frequency transition resolves and the transition is possible. With
disabled interrupts, the blockage doesn't resolve (no matter how long do
we wait). The exact reasons for this hardware behavior are unknown.
This patch enables interrupts in the function speedstep_set_state that can
be called with disabled interrupts. However, this function is called with
disabled interrupts only from speedstep_get_freqs, so it shouldn't cause
any problem.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com
Cc: All applicable <stable@vger.kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Rework of the core ACPI resources parsing code to fix issues
in it and make using resource offsets more convenient and
consolidation of some resource-handing code in a couple of places
that have grown analagous data structures and code to cover the
the same gap in the core (Jiang Liu, Thomas Gleixner, Lv Zheng).
- ACPI-based IOAPIC hotplug support on top of the resources handling
rework (Jiang Liu, Yinghai Lu).
- ACPICA update to upstream release 20150204 including an interrupt
handling rework that allows drivers to install raw handlers for
ACPI GPEs which then become entirely responsible for the given GPE
and the ACPICA core code won't touch it (Lv Zheng, David E Box,
Octavian Purdila).
- ACPI EC driver rework to fix several concurrency issues and other
problems related to events handling on top of the ACPICA's new
support for raw GPE handlers (Lv Zheng).
- New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
Subsystem) driver for Intel chips (Ken Xue).
- Two minor fixes of the ACPI LPSS driver (Heikki Krogerus,
Jarkko Nikula).
- Two new blacklist entries for machines (Samsung 730U3E/740U3E and
510R) where the native backlight interface doesn't work correctly
while the ACPI one does (Hans de Goede).
- Rework of the ACPI processor driver's handling of idle states
to make the code more straightforward and less bloated overall
(Rafael J Wysocki).
- Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki,
Yaowei Bai).
- PCI core power management modification to avoid resuming (some)
runtime-suspended devices during system suspend if they are in
the right states already (Rafael J Wysocki).
- New SFI-based cpufreq driver for Intel platforms using SFI
(Srinidhi Kasagar).
- cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
Doug Anderson, Wolfram Sang).
- SkyLake CPU support and other updates for the intel_pstate driver
(Kristen Carlson Accardi, Srinivas Pandruvada).
- cpufreq-dt driver cleanup (Markus Elfring).
- Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).
- Generic power domains core code fixes and cleanups (Ulf Hansson).
- Operating Performance Points (OPP) core code cleanups and kernel
documentation update (Nishanth Menon).
- New dabugfs interface to make the list of PM QoS constraints
available to user space (Nishanth Menon).
- New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).
- New devfreq class (devfreq_event) to provide raw utilization data
to devfreq governors (Chanwoo Choi).
- Assorted minor fixes and cleanups related to power management
(Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist,
Pavel Machek, Todd E Brandt, Wonhong Kwon).
- turbostat updates (Len Brown) and cpupower Makefile improvement
(Sriram Raghunathan).
/
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Merge tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"We have a few new features this time, including a new SFI-based
cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new
devfreq class for providing its governors with raw utilization data
and a new ACPI driver for AMD SoCs.
Still, the majority of changes here are reworks of existing code to
make it more straightforward or to prepare it for implementing new
features on top of it. The primary example is the rework of ACPI
resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with
support for IOAPIC hotplug implemented on top of it, but there is
quite a number of changes of this kind in the cpufreq core, ACPICA,
ACPI EC driver, ACPI processor driver and the generic power domains
core code too.
The most active developer is Viresh Kumar with his cpufreq changes.
Specifics:
- Rework of the core ACPI resources parsing code to fix issues in it
and make using resource offsets more convenient and consolidation
of some resource-handing code in a couple of places that have grown
analagous data structures and code to cover the the same gap in the
core (Jiang Liu, Thomas Gleixner, Lv Zheng).
- ACPI-based IOAPIC hotplug support on top of the resources handling
rework (Jiang Liu, Yinghai Lu).
- ACPICA update to upstream release 20150204 including an interrupt
handling rework that allows drivers to install raw handlers for
ACPI GPEs which then become entirely responsible for the given GPE
and the ACPICA core code won't touch it (Lv Zheng, David E Box,
Octavian Purdila).
- ACPI EC driver rework to fix several concurrency issues and other
problems related to events handling on top of the ACPICA's new
support for raw GPE handlers (Lv Zheng).
- New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
Subsystem) driver for Intel chips (Ken Xue).
- Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko
Nikula).
- Two new blacklist entries for machines (Samsung 730U3E/740U3E and
510R) where the native backlight interface doesn't work correctly
while the ACPI one does (Hans de Goede).
- Rework of the ACPI processor driver's handling of idle states to
make the code more straightforward and less bloated overall (Rafael
J Wysocki).
- Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei
Bai).
- PCI core power management modification to avoid resuming (some)
runtime-suspended devices during system suspend if they are in the
right states already (Rafael J Wysocki).
- New SFI-based cpufreq driver for Intel platforms using SFI
(Srinidhi Kasagar).
- cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
Doug Anderson, Wolfram Sang).
- SkyLake CPU support and other updates for the intel_pstate driver
(Kristen Carlson Accardi, Srinivas Pandruvada).
- cpufreq-dt driver cleanup (Markus Elfring).
- Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).
- Generic power domains core code fixes and cleanups (Ulf Hansson).
- Operating Performance Points (OPP) core code cleanups and kernel
documentation update (Nishanth Menon).
- New dabugfs interface to make the list of PM QoS constraints
available to user space (Nishanth Menon).
- New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).
- New devfreq class (devfreq_event) to provide raw utilization data
to devfreq governors (Chanwoo Choi).
- Assorted minor fixes and cleanups related to power management
(Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel
Machek, Todd E Brandt, Wonhong Kwon).
- turbostat updates (Len Brown) and cpupower Makefile improvement
(Sriram Raghunathan)"
* tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits)
tools/power turbostat: relax dependency on APERF_MSR
tools/power turbostat: relax dependency on invariant TSC
Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS
tools/power turbostat: relax dependency on root permission
ACPI / video: Add disable_native_backlight quirk for Samsung 510R
ACPI / PM: Remove unneeded nested #ifdef
USB / PM: Remove unneeded #ifdef and associated dead code
intel_pstate: provide option to only use intel_pstate with HWP
ACPI / EC: Add GPE reference counting debugging messages
ACPI / EC: Add query flushing support
ACPI / EC: Refine command storm prevention support
ACPI / EC: Add command flushing support.
ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag
ACPI: add AMD ACPI2Platform device support for x86 system
ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
ACPI / EC: Update revision due to raw handler mode.
ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
...
Pull SFI-based cpufreq driver for v3.20 from Len Brown.
* 'sfi' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
cpufreq: Add SFI based cpufreq driver support
SFI: fix compiler warnings
Allow users the option to disable the driver for any hardware
which does not support HWP.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq_cooling_unregister() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To make code more readable and less error prone, lets create a helper macro for
iterating over all available governors.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To make code more readable and less error prone, lets create a helper macro for
iterating over all active policies.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When cpufreq is disabled, the per-cpu variable would have been set to
NULL. Remove this unnecessary check.
[ Changelog from Saravana Kannan. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In __cpufreq_remove_dev_finish(), per-cpu 'cpufreq_cpu_data' needs
to be cleared before calling kobject_put(&policy->kobj) and under
cpufreq_driver_lock. Otherwise, if someone else calls cpufreq_cpu_get()
in parallel with it, they can obtain a non-NULL policy from that after
kobject_put(&policy->kobj) was executed.
Consider this case:
Thread A Thread B
cpufreq_cpu_get()
acquire cpufreq_driver_lock
read-per-cpu cpufreq_cpu_data
kobject_put(&policy->kobj);
kobject_get(&policy->kobj);
...
per_cpu(&cpufreq_cpu_data, cpu) = NULL
And this will result in a warning like this one:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4 at include/linux/kref.h:47
kobject_get+0x41/0x50()
Modules linked in: acpi_cpufreq(+) nfsd auth_rpcgss nfs_acl
lockd grace sunrpc xfs libcrc32c sd_mod ixgbe igb mdio ahci hwmon
...
Call Trace:
[<ffffffff81661b14>] dump_stack+0x46/0x58
[<ffffffff81072b61>] warn_slowpath_common+0x81/0xa0
[<ffffffff81072c7a>] warn_slowpath_null+0x1a/0x20
[<ffffffff812e16d1>] kobject_get+0x41/0x50
[<ffffffff815262a5>] cpufreq_cpu_get+0x75/0xc0
[<ffffffff81527c3e>] cpufreq_update_policy+0x2e/0x1f0
[<ffffffff810b8cb2>] ? up+0x32/0x50
[<ffffffff81381aa9>] ? acpi_ns_get_node+0xcb/0xf2
[<ffffffff81381efd>] ? acpi_evaluate_object+0x22c/0x252
[<ffffffff813824f6>] ? acpi_get_handle+0x95/0xc0
[<ffffffff81360967>] ? acpi_has_method+0x25/0x40
[<ffffffff81391e08>] acpi_processor_ppc_has_changed+0x77/0x82
[<ffffffff81089566>] ? move_linked_works+0x66/0x90
[<ffffffff8138e8ed>] acpi_processor_notify+0x58/0xe7
[<ffffffff8137410c>] acpi_ev_notify_dispatch+0x44/0x5c
[<ffffffff8135f293>] acpi_os_execute_deferred+0x15/0x22
[<ffffffff8108c910>] process_one_work+0x160/0x410
[<ffffffff8108d05b>] worker_thread+0x11b/0x520
[<ffffffff8108cf40>] ? rescuer_thread+0x380/0x380
[<ffffffff81092421>] kthread+0xe1/0x100
[<ffffffff81092340>] ? kthread_create_on_node+0x1b0/0x1b0
[<ffffffff81669ebc>] ret_from_fork+0x7c/0xb0
[<ffffffff81092340>] ? kthread_create_on_node+0x1b0/0x1b0
---[ end trace 89e66eb9795efdf7 ]---
The actual code flow is as follows:
Thread A: Workqueue: kacpi_notify
acpi_processor_notify()
acpi_processor_ppc_has_changed()
cpufreq_update_policy()
cpufreq_cpu_get()
kobject_get()
Thread B: xenbus_thread()
xenbus_thread()
msg->u.watch.handle->callback()
handle_vcpu_hotplug_event()
vcpu_hotplug()
cpu_down()
__cpu_notify(CPU_POST_DEAD..)
cpufreq_cpu_callback()
__cpufreq_remove_dev_finish()
cpufreq_policy_put_kobj()
kobject_put()
cpufreq_cpu_get() gets the policy from per-cpu variable cpufreq_cpu_data
under cpufreq_driver_lock, and once it gets a valid policy it expects it
to not be freed until cpufreq_cpu_put() is called.
But the race happens when another thread puts the kobject first and updates
cpufreq_cpu_data before or later. And so the first thread gets a valid policy
structure and before it does kobject_get() on it, the second one has already
done kobject_put().
Fix this by setting cpufreq_cpu_data to NULL before putting the kobject and that
too under locks.
Reported-by: Ethan Zhao <ethan.zhao@oracle.com>
Reported-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the user has requested an override of the min_perf_pct via
sysfs, then it should be restored whenever policy is updated,
such as on resume. Take the max of whatever the user requested
and whatever the policy is.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When thermal or other subsystem requests to change the policy,
use that irrepective of whether cpufreq policy is PERFORMANCE or
not. Without this change, when thermal subsystem passive policy wants
to reduce performance, it still runs at 100%.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a sysfs interface to display the total number of supported
pstates. This value is independent of whether turbo has been
enabled or disabled.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch adds "turbo_pct" to the intel_pstate sysfs interface.
turbo_pct will display the percentage of the total supported
pstates that are in the turbo range. This value is independent
of whether turbo has been disabled or not.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no possibility of any race on updating last_index, trans_table or
total_trans as these are updated only by cpufreq_stat_notifier_trans() which
will be called sequentially.
The only place where locking is still relevant is: cpufreq_stats_update(), which
updates time_in_state and last_time. This can be called by two thread in
parallel, that may result in races.
The two threads being:
- sysfs read of time_in_state
- and frequency transition that calls cpufreq_stat_notifier_trans().
Remove locking from the first case mentioned above.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We need to call cpufreq_stats_update() to update 'time_in_state' for the last
frequency. This is achieved by calling it from cpufreq_stat_notifier_trans(),
which is called after frequency transition.
But if we detect that the cpu's frequency haven't really changed and its a false
POSTCHANGE notification, we don't really need to update time_in_state.
It wouldn't cause any harm in calling cpufreq_stats_update() but we can avoid
calling it here and call it when the frequency really changes. The result will
be the same but more efficient.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_stats_update() updates time_in_state and nothing else. It should ideally
be updated only in two cases:
- User requested for the current value of time_in_state.
- We have switched states and so need to update time for the last state.
Currently, we are also doing this while user asks for the transition table of
frequencies. It wouldn't do any harm, but no good as well. Its useless here.
Remove it.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'time_in_state' can't be NULL if 'stats' is valid. These are allocated together
and only if time_in_state is allocated successfully, we update policy->stats.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Userspace is free to read value of any file from cpufreq/stats directory once
they are created. __cpufreq_stats_create_table() is creating the sysfs files
first and then allocating resources for them. Though it would be quite difficult
to trigger the racy situation here, but for the sake of keeping sensible code
lets create sysfs entries only after we are ready to go.
This also does some makeup to the routine to make it look better.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CPUFREQ_UPDATE_POLICY_CPU notifications were used only from cpufreq-stats which
doesn't use it anymore. Remove them.
This also decrements values of other notification macros defined after
CPUFREQ_UPDATE_POLICY_CPU by 1 to remove gaps. Hopefully all users are using
macro's instead of direct numbers and so they wouldn't break as macro values are
changed now.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'cpu' field of struct cpufreq_stats isn't used anymore and so can be dropped.
This change makes cpufreq_stats_update_policy_cpu() empty and so that is removed
as well.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'last_cpu' was used only from cpufreq-stats and isn't used anymore. Get rid of
it.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently we name objects of 'struct cpufreq_stats' as 'stat' and 'stats'.
Use 'stats' to make it consistent.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All CPUs sharing a cpufreq policy share stats too. For this reason,
add a stats pointer to struct cpufreq_policy and drop per-CPU variable
cpufreq_stats_table used for accessing cpufreq stats so as to reduce
code complexity.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is better to pass a struct cpufreq_stats pointer to cpufreq_stats_update()
instead of a CPU number, because that's all it needs.
Even if we pass a cpu number to cpufreq_stats_update(), it reads the per-cpu
variable to get 'stats' out of it. So we are doing these operations
unnecessarily:
- First getting the cpu number to pass to cpufreq_stats_update(), stat->cpu.
- And then getting stats from the cpu, per_cpu(cpufreq_stats_table, cpu).
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While we allocate stats, we do need to check if freq-table is present
or not as we need to use it then. But while freeing stats, all we need
to know is if stats holds a valid pointer value. There is no use of
testing if cpufreq table is present or not.
Don't check it.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'cur_time' is defined in the first line and is then assigned a value
in the next line. Initialize it while defining it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It was never used, but is there since the first commit. Remove it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_stats_create_table() is called from:
- cpufreq notifier on creation of a new policy. Stats will always be
NULL here.
- cpufreq_stats_init() for all CPUs as cpufreq-stats might have been
initialized after cpufreq driver. For any policy, 'stats' will be
NULL for the first CPU only and will be valid for all other CPUs
managed by the same policy.
While we return for other CPUs, we don't return the right error value.
It's not that we would fail with -EBUSY. But generally, this is what
these return values mean:
- EBUSY: we are busy right now, try again. And the retry attempt might
be immediate.
- EEXIST: We already have what you are trying to create and there is no
need to create it again, and so no more tries are required.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The MODULE_DESCRIPTION() string is just too long and then is broken into
multiple lines just to make checkpatch happy.
Rewrite it to make it more precise.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We need to initialize completion and work only on policy allocation and not
really on the policy restore side and so we better move this piece of code to
cpufreq_policy_alloc().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CPUFREQ_STICKY flag is set by drivers which don't want to get unregistered
even if cpufreq-core isn't able to initialize policy for any CPU.
When this flag isn't set, we try to unregister the driver. To find out
which CPUs are registered and which are not, we try to check per_cpu
cpufreq_cpu_data for all CPUs. Because we have a list of valid policies
available now, we better check if the list is empty or not instead of
the 'for' loop. That will be much more efficient.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
These variables are just used within adjust_jiffies() and so must be
local to it. Also there is no need of a dummy routine for CONFIG_SMP
case as we can take care of all that with help of macros in the same
routine. It doesn't look that ugly.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We just need to check if a 'policy' is already present for the cpu we are
adding. We don't need to take all the locks and do kobject usage updates. Use
the light-weight cpufreq_cpu_get_raw() routine instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no need of this separate variable, use 'policy' instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
These are messing up more than the benefit they provide. It isn't
a lot of code anyway, that we will compile without them.
Kill them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We should first check if a cpufreq driver is already registered or not
before updating driver_data->flags.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no point finding out the 'policy' again within __cpufreq_get()
when all the callers already have it. Just make them pass policy instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no point finding out the 'policy' again within cpufreq_out_of_sync()
when all the callers already have it. Just make them pass policy instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Either we can be setpolicy or target type, nothing else. And so the
else part of setpolicy will automatically be of has_target() type.
And so we don't need to check it again.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove unnecessary from find_governor's name.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are two 'if' blocks here, checking for !cpufreq_driver->setpolicy and
has_target(). Both are actually doing the same thing, merge them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
No need of an unnecessary line break.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We can live without it and so we should.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It doesn't make any sense at all and is a leftover of some earlier commit.
Remove it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We should stop cpufreq governors when we shut down the system. If we
don't do this, we can end up with this deadlock:
1. cpufreq governor may be running on a CPU other than CPU0.
2. In machine_restart() we call smp_send_stop() which stops CPUs.
If one of these CPUs was actively running a cpufreq governor
then it may have the mutex / spinlock needed to access the main
PMIC in the system (perhaps over I2C)
3. If a machine needs access to the main PMIC in order to shutdown
then it will never get it since the mutex was lost when the other
CPU stopped.
4. We'll hang (possibly eventually hitting the hard lockup detector).
Let's avoid the problem by stopping the cpufreq governor at shutdown,
which is a sensible thing to do anyway.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This platform_driver does not need to set an owner, it will be
populated by the driver core.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.
The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.
If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.
text data bss dec hex filename
2007 0 0 2007 7d7 kernel/rcu/srcu.o
Size of arch/powerpc/boot/zImage changes from
text data bss dec hex filename
831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before
829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after
so the savings are about ~2000 bytes.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
Rafael J. Wysocki