Commit Graph

90 Commits

Author SHA1 Message Date
Viresh Kumar 1afb9c539d thermal/cpu_cooling: update policy limits if clipped_freq < policy->max
policy->max is the maximum allowed frequency defined by user and
clipped_freq is the maximum that thermal constraints allow.

If clipped_freq is lower than policy->max, then we need to readjust
policy->max.

But, if clipped_freq is greater than policy->max, we don't need to do
anything. We used to call cpufreq_verify_within_limits() in this case,
but it doesn't change anything in this case.

Lets skip this unnecessary call and write a comment that explains this.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:23 -07:00
Viresh Kumar abcbcc25cb thermal/cpu_cooling: rename max_freq as clipped_freq in notifier
That's what it is for, lets name it properly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:23 -07:00
Viresh Kumar 59f0d21883 thermal/cpu_cooling: rename cpufreq_val as clipped_freq
That's what it is for, lets name it properly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:22 -07:00
Viresh Kumar a24af233a1 thermal/cpu_cooling: convert 'switch' block to 'if' block in notifier
We just need to take care of single event here and there is no need to
increase indentation level of most of the code (which causes lines
longer that 80 columns to break).

Kill the switch block.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:22 -07:00
Viresh Kumar 166529c9b6 thermal/cpu_cooling: quit early after updating policy
If a valid cpufreq_dev is found for policy->cpu, we should update the
policy and quit the for loop. There is no need to keep traversing the
list of cpufreq_dev's.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:22 -07:00
Viresh Kumar 76fd38ce21 thermal/cpu_cooling: No need to initialize max_freq to 0
Its always set before getting used, don't initialize it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:26:22 -07:00
Russell King 02373d7c69 thermal: cpu_cooling: fix lockdep problems in cpu_cooling
A recent change to the cpu_cooling code introduced a AB-BA deadlock
scenario between the cpufreq_policy_notifier_list rwsem and the
cooling_cpufreq_lock.  This is caused by cooling_cpufreq_lock being held
before the registration/removal of the notifier block (an operation
which takes the rwsem), and the notifier code itself which takes the
locks in the reverse order:

======================================================
[ INFO: possible circular locking dependency detected ]
3.18.0+ #1453 Not tainted
-------------------------------------------------------
rc.local/770 is trying to acquire lock:
 (cooling_cpufreq_lock){+.+.+.}, at: [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc

but task is already holding lock:
 ((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>]  __blocking_notifier_call_chain+0x34/0x68

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 ((cpufreq_policy_notifier_list).rwsem){++++.+}:
       [<c06bc3b0>] down_write+0x44/0x9c
       [<c0043444>] blocking_notifier_chain_register+0x28/0xd8
       [<c04ad610>] cpufreq_register_notifier+0x68/0x90
       [<c04abe4c>] __cpufreq_cooling_register.part.1+0x120/0x180
       [<c04abf44>] __cpufreq_cooling_register+0x98/0xa4
       [<c04abf8c>] cpufreq_cooling_register+0x18/0x1c
       [<bf0046f8>] imx_thermal_probe+0x1c0/0x470 [imx_thermal]
       [<c037cef8>] platform_drv_probe+0x50/0xac
       [<c037b710>] driver_probe_device+0x114/0x234
       [<c037b8cc>] __driver_attach+0x9c/0xa0
       [<c0379d68>] bus_for_each_dev+0x5c/0x90
       [<c037b204>] driver_attach+0x24/0x28
       [<c037ae7c>] bus_add_driver+0xe0/0x1d8
       [<c037c0cc>] driver_register+0x80/0xfc
       [<c037cd80>] __platform_driver_register+0x50/0x64
       [<bf007018>] 0xbf007018
       [<c0008a5c>] do_one_initcall+0x88/0x1d8
       [<c0095da4>] load_module+0x1768/0x1ef8
       [<c0096614>] SyS_init_module+0xe0/0xf4
       [<c000ec00>] ret_fast_syscall+0x0/0x48

-> #0 (cooling_cpufreq_lock){+.+.+.}:
       [<c00619f8>] lock_acquire+0xb0/0x124
       [<c06ba3b4>] mutex_lock_nested+0x5c/0x3d8
       [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc
       [<c0042bf4>] notifier_call_chain+0x4c/0x8c
       [<c0042f20>] __blocking_notifier_call_chain+0x50/0x68
       [<c0042f58>] blocking_notifier_call_chain+0x20/0x28
       [<c04ae62c>] cpufreq_set_policy+0x7c/0x1d0
       [<c04af3cc>] store_scaling_governor+0x74/0x9c
       [<c04ad418>] store+0x90/0xc0
       [<c0175384>] sysfs_kf_write+0x54/0x58
       [<c01746b4>] kernfs_fop_write+0xdc/0x190
       [<c010dcc0>] vfs_write+0xac/0x1b4
       [<c010dfec>] SyS_write+0x44/0x90
       [<c000ec00>] ret_fast_syscall+0x0/0x48

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((cpufreq_policy_notifier_list).rwsem);
                               lock(cooling_cpufreq_lock);
                               lock((cpufreq_policy_notifier_list).rwsem);
  lock(cooling_cpufreq_lock);

 *** DEADLOCK ***

7 locks held by rc.local/770:
 #0:  (sb_writers#6){.+.+.+}, at: [<c010dda0>] vfs_write+0x18c/0x1b4
 #1:  (&of->mutex){+.+.+.}, at: [<c0174678>] kernfs_fop_write+0xa0/0x190
 #2:  (s_active#52){.+.+.+}, at: [<c0174680>] kernfs_fop_write+0xa8/0x190
 #3:  (cpu_hotplug.lock){++++++}, at: [<c0026a60>] get_online_cpus+0x34/0x90
 #4:  (cpufreq_rwsem){.+.+.+}, at: [<c04ad3e0>] store+0x58/0xc0
 #5:  (&policy->rwsem){+.+.+.}, at: [<c04ad3f8>] store+0x70/0xc0
 #6:  ((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>] __blocking_notifier_call_chain+0x34/0x68

stack backtrace:
CPU: 0 PID: 770 Comm: rc.local Not tainted 3.18.0+ #1453
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
[<c00121c8>] (dump_backtrace) from [<c0012360>] (show_stack+0x18/0x1c)
 r6:c0b85a80 r5:c0b75630 r4:00000000 r3:00000000
[<c0012348>] (show_stack) from [<c06b6c48>] (dump_stack+0x7c/0x98)
[<c06b6bcc>] (dump_stack) from [<c06b42a4>] (print_circular_bug+0x28c/0x2d8)
 r4:c0b85a80 r3:d0071d40
[<c06b4018>] (print_circular_bug) from [<c00613b0>] (__lock_acquire+0x1acc/0x1bb0)
 r10:c0b50660 r8:c09e6d80 r7:d0071d40 r6:c11d0f0c r5:00000007 r4:d0072240
[<c005f8e4>] (__lock_acquire) from [<c00619f8>] (lock_acquire+0xb0/0x124)
 r10:00000000 r9:c04abfc4 r8:00000000 r7:00000000 r6:00000000 r5:c0a06f0c
 r4:00000000
[<c0061948>] (lock_acquire) from [<c06ba3b4>] (mutex_lock_nested+0x5c/0x3d8)
 r10:ec853800 r9:c0a06ed4 r8:d0071d40 r7:c0a06ed4 r6:c11d0f0c r5:00000000
 r4:c04abfc4
[<c06ba358>] (mutex_lock_nested) from [<c04abfc4>] (cpufreq_thermal_notifier+0x34/0xfc)
 r10:ec853800 r9:ec85380c r8:d00d7d3c r7:c0a06ed4 r6:d00d7d3c r5:00000000
 r4:fffffffe
[<c04abf90>] (cpufreq_thermal_notifier) from [<c0042bf4>] (notifier_call_chain+0x4c/0x8c)
 r7:00000000 r6:00000000 r5:00000000 r4:fffffffe
[<c0042ba8>] (notifier_call_chain) from [<c0042f20>] (__blocking_notifier_call_chain+0x50/0x68)
 r8:c0a072a4 r7:00000000 r6:d00d7d3c r5:ffffffff r4:c0a06fc8 r3:ffffffff
[<c0042ed0>] (__blocking_notifier_call_chain) from [<c0042f58>] (blocking_notifier_call_chain+0x20/0x28)
 r7:ec98b540 r6:c13ebc80 r5:ed76e600 r4:d00d7d3c
[<c0042f38>] (blocking_notifier_call_chain) from [<c04ae62c>] (cpufreq_set_policy+0x7c/0x1d0)
[<c04ae5b0>] (cpufreq_set_policy) from [<c04af3cc>] (store_scaling_governor+0x74/0x9c)
 r7:ec98b540 r6:0000000c r5:ec98b540 r4:ed76e600
[<c04af358>] (store_scaling_governor) from [<c04ad418>] (store+0x90/0xc0)
 r6:0000000c r5:ed76e6d4 r4:ed76e600
[<c04ad388>] (store) from [<c0175384>] (sysfs_kf_write+0x54/0x58)
 r8:0000000c r7:d00d7f78 r6:ec98b540 r5:0000000c r4:ec853800 r3:0000000c
[<c0175330>] (sysfs_kf_write) from [<c01746b4>] (kernfs_fop_write+0xdc/0x190)
 r6:ec98b540 r5:00000000 r4:00000000 r3:c0175330
[<c01745d8>] (kernfs_fop_write) from [<c010dcc0>] (vfs_write+0xac/0x1b4)
 r10:0162aa70 r9:d00d6000 r8:0000000c r7:d00d7f78 r6:0162aa70 r5:0000000c
 r4:eccde500
[<c010dc14>] (vfs_write) from [<c010dfec>] (SyS_write+0x44/0x90)
 r10:0162aa70 r8:0000000c r7:eccde500 r6:eccde500 r5:00000000 r4:00000000
[<c010dfa8>] (SyS_write) from [<c000ec00>] (ret_fast_syscall+0x0/0x48)
 r10:00000000 r8:c000edc4 r7:00000004 r6:000216cc r5:0000000c r4:0162aa70

Solve this by moving to finer grained locking - use one mutex to protect
the cpufreq_dev_list as a whole, and a separate lock to ensure correct
ordering of cpufreq notifier registration and removal.

cooling_list_lock is taken within cooling_cpufreq_lock on
(un)registration to preserve the behavior of the code, i.e. to
atomically add/remove to the list and (un)register the notifier.

Fixes: 2dcd851fe4 ("thermal: cpu_cooling: Update always cpufreq policy with
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-08-14 18:21:41 -07:00
Kapileshwar Singh dd658e0235 thermal: cpu_cooling: Fix power calculation when CPUs are offline
Ensure that the CPU for which the frequency is being requested
is online. If none of the CPUs are online the requested power is
returned as 0.

Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Kapileshwar Singh <kapileshwar.singh@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:54 -07:00
Kapileshwar Singh 54b92aae83 thermal: cpu_cooling: Remove cpu_dev update on policy CPU update
It was initially understood that an update to the cpu_device
(cached in cpufreq_cooling_device) was required to ascertain the
correct operating point of the device on a cpufreq policy->cpu update
or creation or deletion of a cpufreq policy.
(e.g. when the existing policy CPU goes offline).

This update is not required and it is possible to ascertain the OPPs
from the leading CPU in a cpufreq domain even if the CPU is hotplugged out.

Fixes: e0128d8ab423 ("thermal: cpu_cooling: implement the power cooling device API")
Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Kapileshwar Singh <kapileshwar.singh@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:54 -07:00
Javi Merino 0cdf97e1ad thermal: cpu_cooling: Check memory allocation of power_table
We allocate the power_table in memory but we don't test whether the
allocation succeeded.  Return -ENOMEM if kcalloc() fails.

Fixes: e0128d8ab423 ("thermal: cpu_cooling: implement the power cooling device API")
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:54 -07:00
Javi Merino 6828a4711f thermal: add trace events to the power allocator governor
Add trace events for the power allocator governor and the power actor
interface of the cpu cooling device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:52 -07:00
Javi Merino c36cf07176 thermal: cpu_cooling: implement the power cooling device API
Add a basic power model to the cpu cooling device to implement the
power cooling device API.  The power model uses the current frequency,
current load and OPPs for the power calculations.  The cpus must have
registered their OPPs using the OPP library.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Kapileshwar Singh <kapileshwar.singh@arm.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:52 -07:00
Zhang Rui 7429b1e0d0 Merge branches 'thermal-core', 'thermal-soc' and 'thermal-int340x' of .git into next 2014-12-24 10:38:30 +08:00
Javi Merino fc4de356e0 thermal: cpu_cooling: document node in struct cpufreq_cooling_device
The node field of struct cpufreq_cooling_device was reintroduced in
2dcd851fe4 (thermal: cpu_cooling: Update always cpufreq policy with
thermal constraints) but without the documentation that it once had.
Add it back so that all the fields of struct cpufreq_cooling_device
are documented.

Cc: Yadwinder Singh Brar <yadi.brar@samsung.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2014-12-21 21:40:13 +08:00
Dan Carpenter 2d2e95ea8f thermal: cpu_cooling: small memory leak on error
There was a left over return here so the error handling isn't run.
It leads to a small memory leak and a static checker warning.

	drivers/thermal/cpu_cooling.c:351 __cpufreq_cooling_register()
	info: ignoring unreachable code.

Fixes: f6859014c7 ("thermal: cpu_cooling: Store frequencies in descending order")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-17 08:54:04 -04:00
Viresh Kumar 73904cbc1a thermal: cpu_cooling: update copyright tags
Adding my copyright information for two purposes:
- To get cc'd for future patches to review (Only if people read this header
  while sending mail)
- Have done enough changes to earn a place here?

Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:12:37 -04:00
Viresh Kumar 4843c4a190 thermal: cpu_cooling: Use cpufreq_dev->freq_table for finding level/freq
get_property() was an over complicated beast with BUGs. It used to believe that
cpufreq table is present in ascending or descending order, which might not
always be true.

Previous patch has created another freq table in descending order for us and we
better use it now. With that get_property() simply goes away and another helper
get_level() comes in.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:11:54 -04:00
Viresh Kumar f6859014c7 thermal: cpu_cooling: Store frequencies in descending order
CPUFreq framework *doesn't* guarantee that frequencies present in cpufreq table
will be in ascending or descending order. But cpu_cooling somehow assumes that.

Probably because most of current users are creating this list from DT, which is
done with the help of OPP layer. And OPP layer creates the list in ascending
order of frequencies.

But cpu_cooling can be used for other platforms too, which don't have
frequencies arranged in any order.

This patch tries to fix this issue by creating another list of valid frequencies
in descending order. Care is also taken to throw warnings for duplicate entries.

Later patches would use it to simplify code.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:11:02 -04:00
Viresh Kumar b9f8b41603 thermal: cpu_cooling: Pass 'cpufreq_dev' to get_property()
We already know the value of 'cpufreq_dev->max_level' and so there is no need
calculating that once again. For this, we need to send 'cpufreq_dev' to
get_property().

Make all necessary changes for this change. Because cpufreq_cooling_get_level()
doesn't have access to 'cpufreq_dev', it is updated to iterate over the list of
cpufreq_cooling_devices to get cooling device for the cpu number passed to it.
This also makes it robust to return levels only for the CPU registered via a
cooling device. We don't have to support anything that isn't registered yet.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:10:08 -04:00
Viresh Kumar 2479bb6443 thermal: cpu_cooling: use cpufreq_dev_list instead of cpufreq_dev_count
As we already have a list of cpufreq_cooling_devices now, lets use it instead of
a local counter.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:09:15 -04:00
Viresh Kumar 97afa4aafb thermal: cpu_cooling: get_property() doesn't need to support GET_MAXL anymore
We don't use get_property() to find max levels anymore as it is done at boot
now. So, don't support GET_MAXL in get_property().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:08:05 -04:00
Viresh Kumar dcc6c7fdef thermal: cpu_cooling: find max level during device registration
CPU frequency tables don't update after the driver is registered and so we don't
need to iterate over them to find total number of states every time
cpufreq_get_max_state() is called. Do it once at boot time.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:07:10 -04:00
Viresh Kumar 521a2e5831 thermal: cpu_cooling: remove unnecessary wrapper get_cpu_frequency()
get_cpu_frequency() isn't doing much by itself, just calling get_property(). And
so this wrapper isn't required at all. Get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:05:53 -04:00
Viresh Kumar 5194fe4699 thermal: cpu_cooling: Merge cpufreq_apply_cooling() into cpufreq_set_cur_state()
cpufreq_apply_cooling() has a single caller, cpufreq_set_cur_state() and
cpufreq_set_cur_state() is an unnecessary wrapper over cpufreq_apply_cooling().

Get rid of it by merging both routines.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 14:04:56 -04:00
Viresh Kumar 7adb635b3c thermal: cpu_cooling: initialize 'cpufreq_val' on registration
There is no point checking for validity of 'cpufreq_val' from
cpufreq_thermal_notifier() every time the routine is called. Its guaranteed to
be 0 on the first call but will be valid otherwise.

Lets update it once while the device registers.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:09:52 -04:00
Viresh Kumar 730abe064b thermal: cpu_cooling: do error handling at the bottom in __cpufreq_cooling_register()
This makes life easy and bug free. And is scalable for future resource
allocations.

Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:57 -04:00
Viresh Kumar c9ca319f05 thermal: cpu_cooling: Don't check is_cpufreq_valid()
Because get_cpu_frequency() has returned a valid frequency, it means that the
cpufreq policy is surely valid and so no point checking that again with
is_cpufreq_valid(). Get rid of the routine as well as there are no more users.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:57 -04:00
Viresh Kumar e1fae554fb thermal: cpu_cooling: don't iterate over all allowed_cpus to update cpufreq policy
All CPUs present in 'allowed_cpus' share the same 'struct cpufreq_policy'
structure and so calling cpufreq_update_policy() for each of them doesn't make
sense.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:56 -04:00
Viresh Kumar 405fb82562 thermal: cpu_cooling: Don't match min/max frequencies for all CPUs on cooling register
In __cpufreq_cooling_register() we try to match min/max frequencies for all CPUs
passed in 'clip_cpus' mask. This mask is the cpumask of cpus where the frequency
constraints will be applied.

Same frequency constraint can be applied only to the CPUs belonging to the same
cluster (i.e. CPUs sharing clock line). For all such CPUs we have a single
'struct cpufreq_policy' structure managing them and so getting policies for all
CPUs wouldn't make any sense as they will all return the same pointer.

So, remove this useless check of checking min/max for all CPUs. Also update doc
comment to make this more obvious that clip_cpus should be same as
policy->related_cpus.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:56 -04:00
Viresh Kumar 268ac445ee thermal: cpu_cooling: propagate error returned by idr_alloc()
We aren't supposed to return our own error type here. Return what we got.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:56 -04:00
Viresh Kumar 8e54d442fe thermal: cpu_cooling: no need to initialze 'ret'
ret is initialized before it is used, so no need to set it to 0 in its declaration.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:56 -04:00
Viresh Kumar 5d3bdb8998 thermal: cpu_cooling: no need to set cpufreq_dev to NULL
It will be overwritten soon with return value of kzalloc().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:55 -04:00
Viresh Kumar 92e615ec82 thermal: cpu_cooling: no need to set cpufreq_state to zero
Its already zero, we allocated cpufreq_dev with kzalloc.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:55 -04:00
Viresh Kumar 98d522f056 thermal: cpu_cooling: Pass variable instead of its type to sizeof()
Just following coding guidelines here.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:55 -04:00
Viresh Kumar 07d888d831 thermal: cpu_cooling: Add comment to clarify relation between cooling state and frequency
This wasn't explained well anywhere and should be clearly specified. Lets add a
top level comment for this.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:55 -04:00
Viresh Kumar beca6053fc thermal: cpu_cooling: fix doc comment over struct cpufreq_cooling_device
cooling_cpufreq_lock isn't used to protect this structure and so the comment
over it is outdated. Fix it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:54 -04:00
Viresh Kumar 728c03c959 thermal: cpu_cooling: random comment fixups
s/give/given

Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:54 -04:00
Eduardo Valentin 0f1be51c35 thermal: cpu_cooling: check for the readiness of cpufreq layer
In this patch, the cpu_cooling code checks for the usability of cpufreq
layer before proceeding with the CPU cooling device registration. The
main reason is: CPU cooling device is not usable if cpufreq cannot
switch frequencies.

Similar checks are spread in thermal drivers. Thus, the advantage now
is to have the check in a single place: cpu cooling device registration.
For this reason, this patch also updates the existing drivers that
depend on CPU cooling to simply propagate the error code of the cpu
cooling registration call. Therefore, in case cpufreq is not ready, the
thermal drivers will still return -EPROBE_DEFER, in an attempt to try
again when cpufreq layer gets ready.

Cc: devicetree@vger.kernel.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-12-08 12:08:53 -04:00
Yadwinder Singh Brar 2dcd851fe4 thermal: cpu_cooling: Update always cpufreq policy with thermal constraints
Existing code updates cupfreq policy only while executing
cpufreq_apply_cooling() function (i.e. when notify_device != NOTIFY_INVALID).
It doesn't apply constraints when cpufreq policy update happens from any other
place but it should update the cpufreq policy with thermal constraints every
time when there is a cpufreq policy update, to keep state of
cpufreq_cooling_device and max_feq of cpufreq policy in sync. For instance
while resuming cpufreq updates cpufreq_policy and it restores default
policy->usr_policy values irrespective of cooling device's cpufreq_state since
notification gets missed because (notify_device == NOTIFY_INVALID).
Another problem, is that userspace is able to change max_freq irrespective of
cooling device's state, as notification gets missed.

This patch modifies code to maintain a global cpufreq_dev_list and applies
constraints of all matching cooling devices for policy's cpu when there is any
policy update(ends up applying the lowest max_freq among the matching cpu
cooling devices).

This patch also removes redundant check (max_freq > policy->user_policy.max),
as cpufreq framework takes care of user_policy constraints already where ever
required, otherwise its causing an issue while increasing max_freq in normal
scenerio as it restores max_freq with policy->user_policy.max which is old
(smaller) value.

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-11-20 18:17:11 -04:00
Javi Merino 9746b6e726 thermal: cpu_cooling: fix typo highjack -> hijack
Cc: Eduardo Valentin <eduardo.valentin@ti.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2014-07-22 10:12:05 +08:00
Stratos Karafotis 3c84ef3af7 thermal: cpu_cooling: Use cpufreq_for_each_valid_entry macro for iteration
The cpufreq core now supports the cpufreq_for_each_valid_entry macro
helper for iteration over the cpufreq_frequency_table, so use it.

Also remove the redundant !! operator.

It should have no functional changes.

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>
2014-04-30 00:06:49 +02:00
Zhang Rui 201531c277 Merge branches 'misc', 'soc', 'soc-eduardo' and 'int3404-thermal' of .git into next 2014-01-02 14:22:28 +08:00
Zhang Rui a116776f7b Thermal cpu cooling: return error if no valid cpu frequency entry
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2014-01-02 11:59:18 +08:00
Eduardo Valentin 1c9573a40c thermal: fix cpu_cooling max_level behavior
As per Documentation/thermal/sysfs-api.txt, max_level
is an index, not a counter. Thus, in case a CPU has
3 valid frequencies, max_level is expected to be 2, for instance.

The current code makes max_level == number of valid frequencies,
which is bogus. This patch fix the cpu_cooling device by
ranging max_level properly.

Reported-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2014-01-02 11:54:14 +08:00
Eduardo Valentin 39d99cff76 thermal: cpu_cooling: introduce of_cpufreq_cooling_register
This patch introduces an API to register cpufreq cooling device
based on device tree node.

The registration via device tree node differs from normal
registration due to the fact that it is needed to fill
the device_node structure in order to be able to match
the cooling devices with trip points.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
2013-12-04 09:33:34 -04:00
Wei Yongjun 73b9bcd76d thermal: cpu_cooling: fix return value check in cpufreq_cooling_register()
In case of error, the function thermal_cooling_device_register() returns
ERR_PTR() and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-11-06 13:16:49 +08:00
Eduardo Valentin 50e66c7ed8 drivers: thermal: add check when unregistering cpu cooling
This patch avoids NULL pointer accesses while unregistering
cpu cooling devices, in case a NULL pointer is received.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
2013-09-03 09:10:34 -04:00
Lan Tianyu 044d5c26da Thermal/cpu_cooling: Return directly for the cpu out of allowed_cpus in the cpufreq_thermal_notifier()
cpufreq_thermal_notifier() is to change the cpu's cpufreq in the allowed_cpus mask
when associated thermal-cpufreq cdev's cooling state is changed. It's a cpufreq policy
notifier handler and it will be triggered even if those cpus out of allowed_cpus has
changed freq policy.

cpufreq_thermal_notifier() checks the policy->cpu. If it belongs to allowed_cpus,
change max_freq(default to 0) to the desire cpufreq value and pass 0 and max_freq
to cpufreq_verify_within_limits() as cpufreq scope. But if not, do nothing and
max_freq will remain 0. This will cause the cpufreq scope to become 0~0. This
is not right. This patch is to return directly after finding cpu not belonging
to allowed_cpus.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-08-15 15:25:08 +08:00
Shawn Guo 24c7a38172 thermal: cpu_cooling: fix 'descend' check in get_property()
The variable 'descend' is initialized as -1 in function get_property(),
and will never get any chance to be updated by the following code.

	if (freq != CPUFREQ_ENTRY_INVALID && descend != -1)
		descend = !!(freq > table[i].frequency);

This makes function get_property() return the wrong frequency for given
cooling level if the frequency table is sorted in ascending.  Fix it
by correcting the 'descend' check in if-condition to 'descend == -1'.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-05-28 14:49:31 +08:00
Eduardo Valentin 5fda7f680a thermal: cpu_cooling: alignment improvements
Improve code readiness by changing alignments so that
they match open parenthesis, like checkpatch.pl --strict
suggests.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-04-27 09:25:55 +08:00