linux-toradex.git/drivers/cpufreq, branch v3.10.24

cpufreq: highbank-cpufreq: Enable Midway/ECX-2000

2013-12-04T18:57:18+00:00

commit fbbc5bfb44a22e7a8ef753a1c8dfb448d7ac8b85 upstream.

Calxeda's new ECX-2000 part uses the same cpufreq interface as highbank,
so add it to the driver's compatibility list.

This is a minor change that can safely be applied to the 3.10 and 3.11
stable trees.

Signed-off-by: Mark Langsdorf 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq / intel_pstate: Fix max_perf_pct on resume

2013-11-13T03:05:30+00:00

commit 52e0a509e5d6f902ec26bc2a8bb02b137dc453be upstream.

If the system is suspended while max_perf_pct is less than 100 percent
or no_turbo set policy->{min,max} will be set incorrectly with scaled
values which turn the scaled values into hard limits.

References: https://bugzilla.kernel.org/show_bug.cgi?id=61241
Reported-by: Patrick Bartels 
Signed-off-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: rename ignore_nice as ignore_nice_load

2013-08-15T05:59:06+00:00

commit 6c4640c3adfd97ce10efed7c07405f52d002b9a8 upstream.

This sysfs file was called ignore_nice_load earlier and commit
4d5dcc4 (cpufreq: governor: Implement per policy instances of
governors) changed its name to ignore_nice by mistake.

Lets get it renamed back to its original name.

Reported-by: Martin von Gagern 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: loongson2: fix regression related to clock management

2013-08-15T05:59:06+00:00

commit f54fe64d14dff3df6d45a48115d248a82557811f upstream.

Commit 42913c799 (MIPS: Loongson2: Use clk API instead of direct
dereferences) broke the cpufreq functionality on Loongson2 boards:
clk_set_rate() is called before the CPU frequency table is
initialized, and therefore will always fail.

Fix by moving the clk_set_rate() after the table initialization.
Tested on Lemote FuLoong mini-PC.

Signed-off-by: Aaro Koskinen 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix cpufreq driver module refcount balance after suspend/resume

2013-08-12T01:35:24+00:00

commit 2a99859932281ed6c2ecdd988855f8f6838f6743 upstream.

Since cpufreq_cpu_put() called by __cpufreq_remove_dev() drops the
driver module refcount, __cpufreq_remove_dev() causes that refcount
to become negative for the cpufreq driver after a suspend/resume
cycle.

This is not the only bad thing that happens there, however, because
kobject_put() should only be called for the policy kobject at this
point if the CPU is not the last one for that policy.

Namely, if the given CPU is the last one for that policy, the
policy kobject's refcount should be 1 at this point, as set by
cpufreq_add_dev_interface(), and only needs to be dropped once for
the kobject to go away.  This actually happens under the cpu == 1
check, so it need not be done before by cpufreq_cpu_put().

On the other hand, if the given CPU is not the last one for that
policy, this means that cpufreq_add_policy_cpu() has been called
at least once for that policy and cpufreq_cpu_get() has been
called for it too.  To balance that cpufreq_cpu_get(), we need to
call cpufreq_cpu_put() in that case.

Thus, to fix the described problem and keep the reference
counters balanced in both cases, move the cpufreq_cpu_get() call
in __cpufreq_remove_dev() to the code path executed only for
CPUs that share the policy with other CPUs.

Reported-and-tested-by: Toralf Förster 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Srivatsa S. Bhat 
Signed-off-by: Greg Kroah-Hartman

cpufreq / intel_pstate: Change to scale off of max P-state

2013-08-04T08:50:51+00:00

commit 2134ed4d614349b2b4e8d7bb593baa9179b8dd1e upstream.

Change to using max P-state instead of max turbo P-state.  This
change resolves two issues.

On a quiet system intel_pstate can fail to respond to a load change.

On CPU SKUs that have a limited number of P-states and no turbo range
intel_pstate fails to select the highest available P-state.

This change is suitable for stable v3.9+

References: https://bugzilla.kernel.org/show_bug.cgi?id=59481
Reported-and-tested-by: Arjan van de Ven 
Reported-and-tested-by: dsmythies@telus.net
Signed-off-by: Dirk Brandewie 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression

2013-07-25T21:07:23+00:00

commit e8d05276f236ee6435e78411f62be9714e0b9377 upstream.

commit 2f7021a8 "cpufreq: protect 'policy->cpus' from offlining
during __gov_queue_work()" caused a regression in CPU hotplug,
because it lead to a deadlock between cpufreq governor worker thread
and the CPU hotplug writer task.

Lockdep splat corresponding to this deadlock is shown below:

[   60.277396] ======================================================
[   60.277400] [ INFO: possible circular locking dependency detected ]
[   60.277407] 3.10.0-rc7-dbg-01385-g241fd04-dirty #1744 Not tainted
[   60.277411] -------------------------------------------------------
[   60.277417] bash/2225 is trying to acquire lock:
[   60.277422]  ((&(&j_cdbs->work)->work)){+.+...}, at: [] flush_work+0x5/0x280
[   60.277444] but task is already holding lock:
[   60.277449]  (cpu_hotplug.lock){+.+.+.}, at: [] cpu_hotplug_begin+0x2b/0x60
[   60.277465] which lock already depends on the new lock.

[   60.277472] the existing dependency chain (in reverse order) is:
[   60.277477] -> #2 (cpu_hotplug.lock){+.+.+.}:
[   60.277490]        [] lock_acquire+0xa4/0x200
[   60.277503]        [] mutex_lock_nested+0x67/0x410
[   60.277514]        [] get_online_cpus+0x3c/0x60
[   60.277522]        [] gov_queue_work+0x2a/0xb0
[   60.277532]        [] cs_dbs_timer+0xc1/0xe0
[   60.277543]        [] process_one_work+0x1cd/0x6a0
[   60.277552]        [] worker_thread+0x121/0x3a0
[   60.277560]        [] kthread+0xdb/0xe0
[   60.277569]        [] ret_from_fork+0x7c/0xb0
[   60.277580] -> #1 (&j_cdbs->timer_mutex){+.+...}:
[   60.277592]        [] lock_acquire+0xa4/0x200
[   60.277600]        [] mutex_lock_nested+0x67/0x410
[   60.277608]        [] cs_dbs_timer+0x8d/0xe0
[   60.277616]        [] process_one_work+0x1cd/0x6a0
[   60.277624]        [] worker_thread+0x121/0x3a0
[   60.277633]        [] kthread+0xdb/0xe0
[   60.277640]        [] ret_from_fork+0x7c/0xb0
[   60.277649] -> #0 ((&(&j_cdbs->work)->work)){+.+...}:
[   60.277661]        [] __lock_acquire+0x1766/0x1d30
[   60.277669]        [] lock_acquire+0xa4/0x200
[   60.277677]        [] flush_work+0x3d/0x280
[   60.277685]        [] __cancel_work_timer+0x8a/0x120
[   60.277693]        [] cancel_delayed_work_sync+0x13/0x20
[   60.277701]        [] cpufreq_governor_dbs+0x529/0x6f0
[   60.277709]        [] cs_cpufreq_governor_dbs+0x17/0x20
[   60.277719]        [] __cpufreq_governor+0x48/0x100
[   60.277728]        [] __cpufreq_remove_dev.isra.14+0x80/0x3c0
[   60.277737]        [] cpufreq_cpu_callback+0x38/0x4c
[   60.277747]        [] notifier_call_chain+0x5d/0x110
[   60.277759]        [] __raw_notifier_call_chain+0xe/0x10
[   60.277768]        [] _cpu_down+0x88/0x330
[   60.277779]        [] cpu_down+0x36/0x50
[   60.277788]        [] store_online+0x98/0xd0
[   60.277796]        [] dev_attr_store+0x18/0x30
[   60.277806]        [] sysfs_write_file+0xdb/0x150
[   60.277818]        [] vfs_write+0xbd/0x1f0
[   60.277826]        [] SyS_write+0x4c/0xa0
[   60.277834]        [] tracesys+0xd0/0xd5
[   60.277842] other info that might help us debug this:

[   60.277848] Chain exists of:
  (&(&j_cdbs->work)->work) --> &j_cdbs->timer_mutex --> cpu_hotplug.lock

[   60.277864]  Possible unsafe locking scenario:

[   60.277869]        CPU0                    CPU1
[   60.277873]        ----                    ----
[   60.277877]   lock(cpu_hotplug.lock);
[   60.277885]                                lock(&j_cdbs->timer_mutex);
[   60.277892]                                lock(cpu_hotplug.lock);
[   60.277900]   lock((&(&j_cdbs->work)->work));
[   60.277907]  *** DEADLOCK ***

[   60.277915] 6 locks held by bash/2225:
[   60.277919]  #0:  (sb_writers#6){.+.+.+}, at: [] vfs_write+0x1c3/0x1f0
[   60.277937]  #1:  (&buffer->mutex){+.+.+.}, at: [] sysfs_write_file+0x3c/0x150
[   60.277954]  #2:  (s_active#61){.+.+.+}, at: [] sysfs_write_file+0xc3/0x150
[   60.277972]  #3:  (x86_cpu_hotplug_driver_mutex){+.+...}, at: [] cpu_hotplug_driver_lock+0x17/0x20
[   60.277990]  #4:  (cpu_add_remove_lock){+.+.+.}, at: [] cpu_down+0x22/0x50
[   60.278007]  #5:  (cpu_hotplug.lock){+.+.+.}, at: [] cpu_hotplug_begin+0x2b/0x60
[   60.278023] stack backtrace:
[   60.278031] CPU: 3 PID: 2225 Comm: bash Not tainted 3.10.0-rc7-dbg-01385-g241fd04-dirty #1744
[   60.278037] Hardware name: Acer             Aspire 5741G    /Aspire 5741G    , BIOS V1.20 02/08/2011
[   60.278042]  ffffffff8204e110 ffff88014df6b9f8 ffffffff815b3d90 ffff88014df6ba38
[   60.278055]  ffffffff815b0a8d ffff880150ed3f60 ffff880150ed4770 3871c4002c8980b2
[   60.278068]  ffff880150ed4748 ffff880150ed4770 ffff880150ed3f60 ffff88014df6bb00
[   60.278081] Call Trace:
[   60.278091]  [] dump_stack+0x19/0x1b
[   60.278101]  [] print_circular_bug+0x2b6/0x2c5
[   60.278111]  [] __lock_acquire+0x1766/0x1d30
[   60.278123]  [] ? __kernel_text_address+0x58/0x80
[   60.278134]  [] lock_acquire+0xa4/0x200
[   60.278142]  [] ? flush_work+0x5/0x280
[   60.278151]  [] flush_work+0x3d/0x280
[   60.278159]  [] ? flush_work+0x5/0x280
[   60.278169]  [] ? mark_held_locks+0x94/0x140
[   60.278178]  [] ? __cancel_work_timer+0x77/0x120
[   60.278188]  [] ? trace_hardirqs_on_caller+0xfd/0x1c0
[   60.278196]  [] __cancel_work_timer+0x8a/0x120
[   60.278206]  [] cancel_delayed_work_sync+0x13/0x20
[   60.278214]  [] cpufreq_governor_dbs+0x529/0x6f0
[   60.278225]  [] cs_cpufreq_governor_dbs+0x17/0x20
[   60.278234]  [] __cpufreq_governor+0x48/0x100
[   60.278244]  [] __cpufreq_remove_dev.isra.14+0x80/0x3c0
[   60.278255]  [] cpufreq_cpu_callback+0x38/0x4c
[   60.278265]  [] notifier_call_chain+0x5d/0x110
[   60.278275]  [] __raw_notifier_call_chain+0xe/0x10
[   60.278284]  [] _cpu_down+0x88/0x330
[   60.278292]  [] ? cpu_hotplug_driver_lock+0x17/0x20
[   60.278302]  [] cpu_down+0x36/0x50
[   60.278311]  [] store_online+0x98/0xd0
[   60.278320]  [] dev_attr_store+0x18/0x30
[   60.278329]  [] sysfs_write_file+0xdb/0x150
[   60.278337]  [] vfs_write+0xbd/0x1f0
[   60.278347]  [] ? fget_light+0x320/0x4b0
[   60.278355]  [] SyS_write+0x4c/0xa0
[   60.278364]  [] tracesys+0xd0/0xd5
[   60.280582] smpboot: CPU 1 is now offline

The intention of that commit was to avoid warnings during CPU
hotplug, which indicated that offline CPUs were getting IPIs from the
cpufreq governor's work items.  But the real root-cause of that
problem was commit a66b2e5 (cpufreq: Preserve sysfs files across
suspend/resume) because it totally skipped all the cpufreq callbacks
during CPU hotplug in the suspend/resume path, and hence it never
actually shut down the cpufreq governor's worker threads during CPU
offline in the suspend/resume path.

Reflecting back, the reason why we never suspected that commit as the
root-cause earlier, was that the original issue was reported with
just the halt command and nobody had brought in suspend/resume to the
equation.

The reason for _that_ in turn, as it turns out, is that earlier
halt/shutdown was being done by disabling non-boot CPUs while tasks
were frozen, just like suspend/resume....  but commit cf7df378a
(reboot: migrate shutdown/reboot to boot cpu) which came somewhere
along that very same time changed that logic: shutdown/halt no longer
takes CPUs offline.  Thus, the test-cases for reproducing the bug
were vastly different and thus we went totally off the trail.

Overall, it was one hell of a confusion with so many commits
affecting each other and also affecting the symptoms of the problems
in subtle ways.  Finally, now since the original problematic commit
(a66b2e5) has been completely reverted, revert this intermediate fix
too (2f7021a8), to fix the CPU hotplug deadlock.  Phew!

Reported-by: Sergey Senozhatsky 
Reported-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Srivatsa S. Bhat 
Tested-by: Peter Wu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Revert commit a66b2e to fix suspend/resume regression

2013-07-25T21:07:23+00:00

commit aae760ed21cd690fe8a6db9f3a177ad55d7e12ab upstream.

commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume)
has unfortunately caused several things in the cpufreq subsystem to
break subtly after a suspend/resume cycle.

The intention of that patch was to retain the file permissions of the
cpufreq related sysfs files across suspend/resume.  To achieve that,
the commit completely removed the calls to cpufreq_add_dev() and
__cpufreq_remove_dev() during suspend/resume transitions.  But the
problem is that those functions do 2 kinds of things:
  1. Low-level initialization/tear-down that are critical to the
     correct functioning of cpufreq-core.
  2. Kobject and sysfs related initialization/teardown.

Ideally we should have reorganized the code to cleanly separate these
two responsibilities, and skipped only the sysfs related parts during
suspend/resume.  Since we skipped the entire callbacks instead (which
also included some CPU and cpufreq-specific critical components),
cpufreq subsystem started behaving erratically after suspend/resume.

So revert the commit to fix the regression.  We'll revisit and address
the original goal of that commit separately, since it involves quite a
bit of careful code reorganization and appears to be non-trivial.

(While reverting the commit, note that another commit f51e1eb
 (cpufreq: Fix cpufreq regression after suspend/resume) already
 reverted part of the original set of changes.  So revert only the
 remaining ones).

Signed-off-by: Srivatsa S. Bhat 
Acked-by: Viresh Kumar 
Tested-by: Paul Bolle 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix cpufreq regression after suspend/resume

2013-07-13T18:42:27+00:00

commit f51e1eb63d9c28cec188337ee656a13be6980cfd upstream.

Toralf Förster reported that the cpufreq ondemand governor behaves erratically
(doesn't scale well) after a suspend/resume cycle. The problem was that the
cpufreq subsystem's idea of the cpu frequencies differed from the actual
frequencies set in the hardware after a suspend/resume cycle. Toralf bisected
the problem to commit a66b2e5 (cpufreq: Preserve sysfs files across
suspend/resume).

Among other (harmless) things, that commit skipped the call to
cpufreq_update_policy() in the resume path. But cpufreq_update_policy() plays
an important role during resume, because it is responsible for checking if
the BIOS changed the cpu frequencies behind our back and resynchronize the
cpufreq subsystem's knowledge of the cpu frequencies, and update them
accordingly.

So, restore the call to cpufreq_update_policy() in the resume path to fix
the cpufreq regression.

Reported-and-tested-by: Toralf Förster 
Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: fix NULL pointer deference at od_set_powersave_bias()

2013-06-25T20:42:37+00:00

When initializing the default powersave_bias value, we need to first
make sure that this policy is running the ondemand governor.

Reported-and-tested-by: Tim Gardner 
Signed-off-by: Jacob Shin 
Signed-off-by: Rafael J. Wysocki