Commit 7c30ed5 (cpufreq: make sure frequency transitions are
serialized) attempted to serialize frequency transitions by
adding checks to the CPUFREQ_PRECHANGE and CPUFREQ_POSTCHANGE
notifications. However, it assumed that the notifications will
always originate from the driver's .target() callback, but they
also can be triggered by cpufreq_out_of_sync() and that leads to
warnings like this on some systems:
WARNING: CPU: 0 PID: 14543 at drivers/cpufreq/cpufreq.c:317
__cpufreq_notify_transition+0x238/0x260()
In middle of another frequency transition
accompanied by a call trace similar to this one:
[<ffffffff81720daa>] dump_stack+0x46/0x58
[<ffffffff8106534c>] warn_slowpath_common+0x8c/0xc0
[<ffffffff815b8560>] ? acpi_cpufreq_target+0x320/0x320
[<ffffffff81065436>] warn_slowpath_fmt+0x46/0x50
[<ffffffff815b1ec8>] __cpufreq_notify_transition+0x238/0x260
[<ffffffff815b33be>] cpufreq_notify_transition+0x3e/0x70
[<ffffffff815b345d>] cpufreq_out_of_sync+0x6d/0xb0
[<ffffffff815b370c>] cpufreq_update_policy+0x10c/0x160
[<ffffffff815b3760>] ? cpufreq_update_policy+0x160/0x160
[<ffffffff81413813>] cpufreq_set_cur_state+0x8c/0xb5
[<ffffffff814138df>] processor_set_cur_state+0xa3/0xcf
[<ffffffff8158e13c>] thermal_cdev_update+0x9c/0xb0
[<ffffffff8159046a>] step_wise_throttle+0x5a/0x90
[<ffffffff8158e21f>] handle_thermal_trip+0x4f/0x140
[<ffffffff8158e377>] thermal_zone_device_update+0x57/0xa0
[<ffffffff81415b36>] acpi_thermal_check+0x2e/0x30
[<ffffffff81415ca0>] acpi_thermal_notify+0x40/0xdc
[<ffffffff813e7dbd>] acpi_device_notify+0x19/0x1b
[<ffffffff813f8241>] acpi_ev_notify_dispatch+0x41/0x5c
[<ffffffff813e3fbe>] acpi_os_execute_deferred+0x25/0x32
[<ffffffff81081060>] process_one_work+0x170/0x4a0
[<ffffffff81082121>] worker_thread+0x121/0x390
[<ffffffff81082000>] ? manage_workers.isra.20+0x170/0x170
[<ffffffff81088fe0>] kthread+0xc0/0xd0
[<ffffffff81088f20>] ? flush_kthread_worker+0xb0/0xb0
[<ffffffff8173582c>] ret_from_fork+0x7c/0xb0
[<ffffffff81088f20>] ? flush_kthread_worker+0xb0/0xb0
For this reason, revert commit 7c30ed5 along with the fix 266c13d
(cpufreq: Fix serialization of frequency transitions) on top of it
and we will revisit the serialization problem later.
Reported-by: Alessandro Bono <alessandro.bono@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are places where the variable 'ret' is declared as unsigned int
and then used to store negative return values such as -EINVAL. Fix them
by declaring the variable as a signed quantity.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit "cpufreq: serialize calls to __cpufreq_governor()" had been a temporary
and partial solution to the race condition between writing to a cpufreq sysfs
file and taking a CPU offline. Now that we have a proper and complete solution
to that problem, remove the temporary fix.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The functions that are used to write to cpufreq sysfs files (such as
store_scaling_max_freq()) are not hotplug safe. They can race with CPU
hotplug tasks and lead to problems such as trying to acquire an already
destroyed timer-mutex etc.
Eg:
__cpufreq_remove_dev()
__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
policy->governor->governor(policy, CPUFREQ_GOV_STOP);
cpufreq_governor_dbs()
case CPUFREQ_GOV_STOP:
mutex_destroy(&cpu_cdbs->timer_mutex)
cpu_cdbs->cur_policy = NULL;
<PREEMPT>
store()
__cpufreq_set_policy()
__cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
policy->governor->governor(policy, CPUFREQ_GOV_LIMITS);
case CPUFREQ_GOV_LIMITS:
mutex_lock(&cpu_cdbs->timer_mutex); <-- Warning (destroyed mutex)
if (policy->max < cpu_cdbs->cur_policy->cur) <- cur_policy == NULL
So use get_online_cpus()/put_online_cpus() in the store_*() functions, to
synchronize with CPU hotplug. However, there is an additional point to note
here: some parts of the CPU teardown in the cpufreq subsystem are done in
the CPU_POST_DEAD stage, with cpu_hotplug.lock *released*. So, using the
get/put_online_cpus() functions alone is insufficient; we should also ensure
that we don't race with those latter steps in the hotplug sequence. We can
easily achieve this by checking if the CPU is online before proceeding with
the store, since the CPU would have been marked offline by the time the
CPU_POST_DEAD notifiers are executed.
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_remove_dev_finish() handles the kobject cleanup for a CPU going
offline. But because we destroy the kobject towards the end of the CPU offline
phase, there are certain race windows where a task can try to write to a
cpufreq sysfs file (eg: using store_scaling_max_freq()) while we are taking
that CPU offline, and this can bump up the kobject refcount, which in turn might
hinder the CPU offline task from running to completion. (It can also cause
other more serious problems such as trying to acquire a destroyed timer-mutex
etc., depending on the exact stage of the cleanup at which the task managed to
take a new refcount).
To fix the race window, we will need to synchronize those store_*() call-sites
with CPU hotplug, using get_online_cpus()/put_online_cpus(). However, that
in turn can cause a total deadlock because it can end up waiting for the
CPU offline task to complete, with incremented refcount!
Write to sysfs CPU offline task
-------------- ----------------
kobj_refcnt++
Acquire cpu_hotplug.lock
get_online_cpus();
Wait for kobj_refcnt to drop to zero
**DEADLOCK**
A simple way to avoid this problem is to perform the kobject cleanup in the
CPU offline path, with the cpu_hotplug.lock *released*. That is, we can
perform the wait-for-kobj-refcnt-to-drop as well as the subsequent cleanup
in the CPU_POST_DEAD stage of CPU offline, which is run with cpu_hotplug.lock
released. Doing this helps us avoid deadlocks due to holding kobject refcounts
and waiting on each other on the cpu_hotplug.lock.
(Note: We can't move all of the cpufreq CPU offline steps to the
CPU_POST_DEAD stage, because certain things such as stopping the governors
have to be done before the outgoing CPU is marked offline. So retain those
parts in the CPU_DOWN_PREPARE stage itself).
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During CPU offline, the cpufreq core invokes __cpufreq_remove_dev()
to perform work such as stopping the cpufreq governor, clearing the
CPU from the policy structure etc, and finally cleaning up the
kobject.
There are certain subtle issues related to the kobject cleanup, and
it would be much easier to deal with them if we separate that part
from the rest of the cleanup-work in the CPU offline phase. So split
the __cpufreq_remove_dev() function into 2 parts: one that handles
the kobject cleanup, and the other that handles the rest of the work.
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The time spent by a CPU under a given frequency is stored in jiffies unit
in the cpu var cpufreq_stats_table->time_in_state[i], i being the index of
the frequency.
This is what is displayed in the following file on the right column:
cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
2301000 19835820
2300000 3172
[...]
Now cpufreq converts this jiffies unit delta to clock_t before returning it
to the user as in the above file. And that conversion is achieved using the API
cputime64_to_clock_t().
Although it accidentally works on traditional tick based cputime accounting, where
cputime_t maps directly to jiffies, it doesn't work with other types of cputime
accounting such as CONFIG_VIRT_CPU_ACCOUNTING_* where cputime_t can map to nsecs
or any granularity preffered by the architecture.
For example we get a buggy zero delta on full dyntick configurations:
cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
2301000 0
2300000 0
[...]
Fix this with using the proper jiffies_64_t to clock_t conversion.
Reported-and-tested-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We can't take a big lock around __cpufreq_governor() as this causes
recursive locking for some cases. But calls to this routine must be
serialized for every policy. Otherwise we can see some unpredictable
events.
For example, consider following scenario:
__cpufreq_remove_dev()
__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
policy->governor->governor(policy, CPUFREQ_GOV_STOP);
cpufreq_governor_dbs()
case CPUFREQ_GOV_STOP:
mutex_destroy(&cpu_cdbs->timer_mutex)
cpu_cdbs->cur_policy = NULL;
<PREEMPT>
store()
__cpufreq_set_policy()
__cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
policy->governor->governor(policy, CPUFREQ_GOV_LIMITS);
case CPUFREQ_GOV_LIMITS:
mutex_lock(&cpu_cdbs->timer_mutex); <-- Warning (destroyed mutex)
if (policy->max < cpu_cdbs->cur_policy->cur) <- cur_policy == NULL
And so store() will eventually result in a crash if cur_policy is
NULL at this point.
Introduce an additional variable which would guarantee serialization
here.
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_governor() returns with -EBUSY when governor is already
stopped and we try to stop it again, but when it is stopped we must
not allow calls to CPUFREQ_GOV_LIMITS event as well.
This patch adds this check in __cpufreq_governor().
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Workqueues are preemptible even if works are queued on them with
queue_work_on(). Let's use raw_smp_processor_id() here to silence
the warning.
BUG: using smp_processor_id() in preemptible [00000000] code: kworker/3:2/674
caller is gov_queue_work+0x28/0xb0
CPU: 0 PID: 674 Comm: kworker/3:2 Tainted: G W 3.10.0 #30
Workqueue: events od_dbs_timer
[<c010c178>] (unwind_backtrace+0x0/0x11c) from [<c0109dec>] (show_stack+0x10/0x14)
[<c0109dec>] (show_stack+0x10/0x14) from [<c03885a4>] (debug_smp_processor_id+0xbc/0xf0)
[<c03885a4>] (debug_smp_processor_id+0xbc/0xf0) from [<c0635864>] (gov_queue_work+0x28/0xb0)
[<c0635864>] (gov_queue_work+0x28/0xb0) from [<c0635618>] (od_dbs_timer+0x108/0x134)
[<c0635618>] (od_dbs_timer+0x108/0x134) from [<c01aa8f8>] (process_one_work+0x25c/0x444)
[<c01aa8f8>] (process_one_work+0x25c/0x444) from [<c01aaf88>] (worker_thread+0x200/0x344)
[<c01aaf88>] (worker_thread+0x200/0x344) from [<c01b03bc>] (kthread+0xa0/0xb0)
[<c01b03bc>] (kthread+0xa0/0xb0) from [<c01061b8>] (ret_from_fork+0x14/0x3c)
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- 'Governer' should be 'Governor'.
- 'S' is used for Siemens (electrical conductance) in SI units,
so use small 's' for seconds.
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Function __cpufreq_driver_target() checks if target_freq is within
policy->min and policy->max range. generic_powersave_bias_target() also
checks if target_freq is valid via a cpufreq_frequency_table_target()
call. So, drop the unnecessary duplicate check in *_check_cpu().
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a CPU is hot removed we'll cancel all the delayed work items
via gov_cancel_work(). Normally this will just cancels a delayed
timer on each CPU that the policy is managing and the work won't
run, but if the work is already running the workqueue code will
wait for the work to finish before continuing to prevent the
work items from re-queuing themselves like they normally do. This
scheme will work most of the time, except for the case where the
work function determines that it should adjust the delay for all
other CPUs that the policy is managing. If this scenario occurs,
the canceling CPU will cancel its own work but queue up the other
CPUs works to run. For example:
CPU0 CPU1
---- ----
cpu_down()
...
__cpufreq_remove_dev()
cpufreq_governor_dbs()
case CPUFREQ_GOV_STOP:
gov_cancel_work(dbs_data, policy);
cpu0 work is canceled
timer is canceled
cpu1 work is canceled <work runs>
<waits for cpu1> od_dbs_timer()
gov_queue_work(*, *, true);
cpu0 work queued
cpu1 work queued
cpu2 work queued
...
cpu1 work is canceled
cpu2 work is canceled
...
At the end of the GOV_STOP case cpu0 still has a work queued to
run although the code is expecting all of the works to be
canceled. __cpufreq_remove_dev() will then proceed to
re-initialize all the other CPUs works except for the CPU that is
going down. The CPUFREQ_GOV_START case in cpufreq_governor_dbs()
will trample over the queued work and debugobjects will spit out
a warning:
WARNING: at lib/debugobjects.c:260 debug_print_object+0x94/0xbc()
ODEBUG: init active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x10
Modules linked in:
CPU: 0 PID: 1491 Comm: sh Tainted: G W 3.10.0 #19
[<c010c178>] (unwind_backtrace+0x0/0x11c) from [<c0109dec>] (show_stack+0x10/0x14)
[<c0109dec>] (show_stack+0x10/0x14) from [<c01904cc>] (warn_slowpath_common+0x4c/0x6c)
[<c01904cc>] (warn_slowpath_common+0x4c/0x6c) from [<c019056c>] (warn_slowpath_fmt+0x2c/0x3c)
[<c019056c>] (warn_slowpath_fmt+0x2c/0x3c) from [<c0388a7c>] (debug_print_object+0x94/0xbc)
[<c0388a7c>] (debug_print_object+0x94/0xbc) from [<c0388e34>] (__debug_object_init+0x2d0/0x340)
[<c0388e34>] (__debug_object_init+0x2d0/0x340) from [<c019e3b0>] (init_timer_key+0x14/0xb0)
[<c019e3b0>] (init_timer_key+0x14/0xb0) from [<c0635f78>] (cpufreq_governor_dbs+0x3e8/0x5f8)
[<c0635f78>] (cpufreq_governor_dbs+0x3e8/0x5f8) from [<c06325a0>] (__cpufreq_governor+0xdc/0x1a4)
[<c06325a0>] (__cpufreq_governor+0xdc/0x1a4) from [<c0633704>] (__cpufreq_remove_dev.isra.10+0x3b4/0x434)
[<c0633704>] (__cpufreq_remove_dev.isra.10+0x3b4/0x434) from [<c08989f4>] (cpufreq_cpu_callback+0x60/0x80)
[<c08989f4>] (cpufreq_cpu_callback+0x60/0x80) from [<c08a43c0>] (notifier_call_chain+0x38/0x68)
[<c08a43c0>] (notifier_call_chain+0x38/0x68) from [<c01938e0>] (__cpu_notify+0x28/0x40)
[<c01938e0>] (__cpu_notify+0x28/0x40) from [<c0892ad4>] (_cpu_down+0x7c/0x2c0)
[<c0892ad4>] (_cpu_down+0x7c/0x2c0) from [<c0892d3c>] (cpu_down+0x24/0x40)
[<c0892d3c>] (cpu_down+0x24/0x40) from [<c0893ea8>] (store_online+0x2c/0x74)
[<c0893ea8>] (store_online+0x2c/0x74) from [<c04519d8>] (dev_attr_store+0x18/0x24)
[<c04519d8>] (dev_attr_store+0x18/0x24) from [<c02a69d4>] (sysfs_write_file+0x100/0x148)
[<c02a69d4>] (sysfs_write_file+0x100/0x148) from [<c0255c18>] (vfs_write+0xcc/0x174)
[<c0255c18>] (vfs_write+0xcc/0x174) from [<c0255f70>] (SyS_write+0x38/0x64)
[<c0255f70>] (SyS_write+0x38/0x64) from [<c0106120>] (ret_fast_syscall+0x0/0x30)
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull cpufreq fixes for v3.12 from Viresh Kumar.
* 'cpufreq-fixes' of git://git.linaro.org/people/vireshk/linux:
cpufreq: imx6q: Fix clock enable balance
cpufreq: tegra: fix the wrong clock name
For changing the cpu frequency the i.MX6q has to be switched to some
intermediate clock during the PLL reprogramming. The driver tries
to be clever to keep the enable count correct but gets it wrong. If
the cpufreq is increased it calls clk_disable_unprepare twice
on pll2_pfd2_396m. This puts all other devices which get their clock
from pll2_pfd2_396m into a nonworking state.
Fix this by removing the clk enabling/disabling altogether since the
clk core will do this automatically during a reparent.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The "cpu" and "pclk_p_cclk" was a virtual clock name that was used in
the legacy Tegra clock framework. It was not used after converting to
CCF. Fix it as the correct clock name that we are using.
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Pull DT/core/cpufreq cpu_ofnode updates for v3.12 from Sudeep KarkadaNagesha.
* 'cpu_of_node' of git://linux-arm.org/linux-skn:
cpufreq: pmac32-cpufreq: remove device tree parsing for cpu nodes
cpufreq: pmac64-cpufreq: remove device tree parsing for cpu nodes
cpufreq: maple-cpufreq: remove device tree parsing for cpu nodes
cpufreq: arm_big_little: remove device tree parsing for cpu nodes
cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes
cpufreq: spear-cpufreq: remove device tree parsing for cpu nodes
cpufreq: highbank-cpufreq: remove device tree parsing for cpu nodes
cpufreq: cpufreq-cpu0: remove device tree parsing for cpu nodes
cpufreq: imx6q-cpufreq: remove device tree parsing for cpu nodes
drivers/bus: arm-cci: avoid parsing DT for cpu device nodes
ARM: mvebu: remove device tree parsing for cpu nodes
ARM: topology: remove hwid/MPIDR dependency from cpu_capacity
of/device: add helper to get cpu device node from logical cpu index
driver/core: cpu: initialize of_node in cpu's device struture
ARM: DT/kernel: define ARM specific arch_match_cpu_phys_id
of: move of_get_cpu_node implementation to DT core library
powerpc: refactor of_get_cpu_node to support other architectures
openrisc: remove undefined of_get_cpu_node declaration
microblaze: remove undefined of_get_cpu_node declaration
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes DT parsing and uses cpu->of_node instead.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Cc: Jason Cooper <jason@lakedaemon.net>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Cc: Deepak Sikri <sikrid@qti.qualcomm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Cc: Mark Langsdorf <mark.langsdorf@calxeda.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.
This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
To iterate over all policies we currently iterate over all online
CPUs and then get the policy for each of them which is suboptimal.
Use the newly created cpufreq_policy_list for this purpose instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_policy_cpu per-cpu variables are used for storing the ID of
the CPU that manages the given CPU's policy. However, we also store
a policy pointer for each cpu in cpufreq_cpu_data, so the
cpufreq_policy_cpu information is simply redundant.
It is better to use cpufreq_cpu_data to retrieve a policy and get
policy->cpu from there, so make that happen everywhere and drop the
cpufreq_policy_cpu per-cpu variables which aren't necessary any more.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We don't need to check if event is CPUFREQ_GOV_POLICY_INIT and put
governor module as we are sure event can only be START/STOP here.
Remove the useless check.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_policy_list is a list of active policies. We do remove
policies from this list when all CPUs belonging to that policy are
removed. But during system suspend we don't really free a policy
struct as it will be used again during resume, so we didn't remove
it from cpufreq_policy_list as well..
However, this is incorrect. We are saying this policy isn't valid
anymore and must not be referenced (though we haven't freed it), but
it can still be used by code that iterates over cpufreq_policy_list.
Remove policy from this list during system suspend as well.
Of course, we must add it back whenever the first CPU belonging to
that policy shows up.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Align closing brace '}' of an if block.
[rjw: Subject and changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit eb60852 (cpufreq: Use cpufreq_policy_list for iterating
over policies), because it breaks system suspend/resume on multiple
machines.
It either causes resume to block indefinitely or causes the BUG_ON()
in lock_policy_rwsem_##mode() to trigger on sysfs accesses to cpufreq
attributes.
Conflicts:
drivers/cpufreq/cpufreq.c
This local symbol is used only in this file.
Fix the following sparse warnings:
drivers/cpufreq/unicore2-cpufreq.c:27:5: warning: symbol 'ucv2_verify_speed' was not declared. Should it be static?
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__init belongs after the return type on functions, not before it.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__init belongs after the return type on functions, not before it.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__init belongs after the return type on functions, not before it.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Replace ARRAY_AND_SIZE(e) in function argument position to avoid
hiding the arity of the called function.
The semantic match that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e,f;
@@
f(...,
- ARRAY_AND_SIZE(e)
+ e,ARRAY_SIZE(e)
,...)
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since NULL could in theory be a valid regulator we ought to check for
IS_ERR() rather than for NULL. In practice this is unlikely to be an
issue but it's better for neatness.
Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Standardise the defintion of the cpb (Core Performance Boost)
attribute in the acpi-cpufreq driver via the cpufreq_freq_attr_rw
macro.
[rjw: Subject and changelog]
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull ARM cpufreq fixes from Viresh Kumar.
* 'cpufreq-fixes' of git://git.linaro.org/people/vireshk/linux:
cpufreq: fix EXYNOS drivers selection
cpufreq: exynos5440: Fix to skip when new frequency same as current
* remove superfluous pr_debug() call from exynos_cpufreq_init()
(init errors are always logged anyway)
* add dummy per-SoC type init functions to exynos-cpufreq.h
* make per-SoC type cpufreq config options selectable
* make CONFIG_ARM_EXYNOS_CPUFREQ config option invisible to user and
automatically enable it when needed
This patch fixes following issues:
* EXYNOS per-SoC type cpufreq support (i.e. exynos4210-cpufreq.c) being
always built if given SoC support was enabled (i.e. CPU_EXYNOS4210),
even if common EXYNOS cpufreq support was disabled
* inability to select cpufreq for each SoC type separately (it could
be only enabled/disabled for all SoCs for which support was enabled)
* EXYNOS5440 cpufreq support was always enabled when EXYNOS5440
support was enabled and couldn't be disabled
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This patch fixes the issue of un-necessary setting the clock controller
when the new target frequency is same as the current one. This case usually
occurs with governors like ondemand which passes the target frequency as the
percentage of average frequency. This check is present in most of the cpufreq
drivers.
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The __cpufreq_governor() function can fail in rare cases especially
if there are bugs in cpufreq drivers. Thus we must stop processing
as soon as this routine fails, otherwise it may result in undefined
behavior.
This patch adds error checking code whenever this routine is called
from any place.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers
as this field isn't used any more by the cpufreq core.
This patch removes it and updates all dependent drivers accordingly.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Critical sections of the cpufreq core are protected with the help of
the driver module owner's refcount, which isn't the correct approach,
because it causes rmmod to return an error when some routine has
updated that refcount.
Let's use rwsem for this purpose instead. Only
cpufreq_unregister_driver() will use write sem
and everybody else will use read sem.
[rjw: Subject & changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq governor owner refcount usage is broken. We should only
increment that refcount when a CPUFREQ_GOV_POLICY_INIT event has come
and it should only be decremented if CPUFREQ_GOV_POLICY_EXIT has come.
Currently, there can be situations where the governor is in use, but
we have allowed it to be unloaded which may result in undefined
behavior. Let's fix it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To iterate over all policies we currently iterate over all CPUs and
then get the policy for each of them. Let's use the newly created
cpufreq_policy_list for this purpose.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Policies available in the cpufreq framework are now linked together.
They are accessible via cpufreq_policy_list defined in the cpufreq
core.
[rjw: Fix from Yinghai Lu folded in]
Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
