linux-stable.git/drivers/cpufreq, branch v3.12.64

cpufreq: Fix GOV_LIMITS handling for the userspace governor

2016-09-29T09:14:17+00:00

commit e43e94c1eda76dabd686ddf6f7825f54d747b310 upstream.

Currently, the userspace governor only updates frequency on GOV_LIMITS
if policy->cur falls outside policy->{min/max}. However, it is also
necessary to update current frequency on GOV_LIMITS to match the user
requested value if it can be achieved within the new policy->{max/min}.

This was previously the behaviour in the governor until commit d1922f0
("cpufreq: Simplify userspace governor") which incorrectly assumed that
policy->cur == user requested frequency via scaling_setspeed. This won't
be true if the user requested frequency falls outside policy->{min/max}.
Ex: a temporary thermal cap throttled the user requested frequency.

Fix this by storing the user requested frequency in a seperate variable.
The governor will then try to achieve this request on every GOV_LIMITS
change.

Fixes: d1922f02562f (cpufreq: Simplify userspace governor)
Signed-off-by: Sai Gurrappadi 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

intel_pstate: Use del_timer_sync in intel_pstate_cpu_stop

2016-04-11T14:43:52+00:00

commit c2294a2f7853e6450361d078b65407bdaa6d1d11 upstream.

Ensure that no timer callback is running since we are about to free
the timer structure.  We cannot guarantee that the call back is called
on the CPU where the timer is running.

Reported-by: Thomas Gleixner 
Signed-off-by: Dirk Brandewie 
Reviewed-by: Srivatsa S. Bhat 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: pcc: Enable autoload of pcc-cpufreq for ACPI processors

2015-06-23T13:56:21+00:00

commit 7e7e8fe69820c6fa31395dbbd8e348e3c69cd2a9 upstream.

The pcc-cpufreq driver is not automatically loaded on systems where
the platform's power management setting requires this driver.
Instead, on those systems no CPU frequency driver is registered and
active.

Make the autoloading matching criteria for loading the pcc-cpufreq
driver the same as done in acpi-cpufreq by commit c655affbd524d01
("ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq").

x86 CPU frequency drivers are now typically autoloaded by specifying
MODULE_DEVICE_TABLE entries and x86cpu model specific matching.
But pcc-cpufreq was omitted when acpi-cpufreq and other drivers were
changed to use this approach.

Both acpi-cpufreq and pcc-cpufreq depend on a distinct and mutually
exclusive set of ACPI methods which are not directly tied to specific
processor model numbers. Both of these drivers have init routines
which look for their required ACPI methods. As a result, only the
appropriate driver registers as the cpu frequency driver and the other
one ends up being unloaded.

Tested on various systems where acpi-cpufreq, intel_pstate, and
pcc-cpufreq are the expected cpu frequency drivers.

Signed-off-by: Lenny Szubowicz 
Signed-off-by: Joseph Szczypek 
Reported-by: Trinh Dao 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: fix a NULL pointer dereference in __cpufreq_governor()

2015-04-27T17:59:53+00:00

commit cb57720bf79688d64854a0a43565aa52303c1f3f upstream.

If ACPI _PPC changed notification happens before governor was initiated
while kernel is booting, a NULL pointer dereference will be triggered:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
 IP: [] __cpufreq_governor+0x23/0x1e0
 PGD 0
 Oops: 0000 [#1] SMP
 ... ...
 RIP: 0010:[]  []
 __cpufreq_governor+0x23/0x1e0
 RSP: 0018:ffff881fcfbcfbb8  EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff881fd11b3980 RCX: ffff88407fc20000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff881fd11b3980
 RBP: ffff881fcfbcfbd8 R08: 0000000000000000 R09: 000000000000000f
 R10: ffffffff818068d0 R11: 0000000000000043 R12: 0000000000000004
 R13: 0000000000000000 R14: ffffffff8196cae0 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff881fffc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000030 CR3: 00000000018ae000 CR4: 00000000000407f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process kworker/0:3 (pid: 750, threadinfo ffff881fcfbce000, task
 ffff881fcf556400)
 Stack:
  ffff881fffc17d00 ffff881fcfbcfc18 ffff881fd11b3980 0000000000000000
  ffff881fcfbcfc08 ffffffff81470d08 ffff881fd11b3980 0000000000000007
  ffff881fcfbcfc18 ffff881fffc17d00 ffff881fcfbcfd28 ffffffff81472e9a
 Call Trace:
  [] __cpufreq_set_policy+0x1b8/0x2e0
  [] cpufreq_update_policy+0xca/0x150
  [] ? cpufreq_update_policy+0x150/0x150
  [] acpi_processor_ppc_has_changed+0x71/0x7b
  [] acpi_processor_notify+0x55/0x115
  [] acpi_device_notify+0x19/0x1b
  [] acpi_ev_notify_dispatch+0x41/0x5f
  [] acpi_os_execute_deferred+0x27/0x34

The root cause is a race conditon -- cpufreq core and acpi-cpufreq driver
were initiated, but cpufreq_governor wasn't and _PPC changed notification
happened, __cpufreq_governor() was called within acpi_os_execute_deferred
kernel thread context.

To fix this panic issue, add pointer checking code in __cpufreq_governor()
before pointer policy->governor is to be dereferenced.

Signed-off-by: Ethan Zhao 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: s3c: remove incorrect __init annotations

2015-03-01T22:34:15+00:00

commit 61882b63171736571e1139ab5aa929e3bb336016 upstream.

The two functions s3c2416_cpufreq_driver_init and s3c_cpufreq_register
are marked init but are called from a context that might be run after
the __init sections are discarded, as the compiler points out:

WARNING: vmlinux.o(.data+0x1ad9dc): Section mismatch in reference from the variable s3c2416_cpufreq_driver to the function .init.text:s3c2416_cpufreq_driver_init()
WARNING: drivers/built-in.o(.text+0x35b5dc): Section mismatch in reference from the function s3c2410a_cpufreq_add() to the function .init.text:s3c_cpufreq_register()

This removes the __init markings.

Signed-off-by: Arnd Bergmann 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: speedstep-smi: enable interrupts when waiting

2015-03-01T22:34:15+00:00

commit d4d4eda23794c701442e55129dd4f8f2fefd5e4d upstream.

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 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

2014-11-13T18:02:38+00:00

commit 36b4bed5cd8f6e17019fa7d380e0836872c7b367 upstream.

Code which changes policy to powersave changes also max_policy_pct based on
max_freq. Code which change max_perf_pct has upper limit base on value
max_policy_pct. When policy is changing from powersave back to performance
then max_policy_pct is not changed. Which means that changing max_perf_pct is
not possible to high values if max_freq was too low in powersave policy.

Test case:

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
800000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
100

$ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
powersave
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
800000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
20

$ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
24

And now intel_pstate driver allows to set maximal value for max_perf_pct based
on max_policy_pct which is 24 for previous powersave max_freq 800000.

This patch will set default value for max_policy_pct when setting policy to
performance so it will allow to set also max value for max_perf_pct.

Signed-off-by: Pali Rohár 
Acked-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers

2014-11-13T18:02:37+00:00

commit c034b02e213d271b98c45c4a7b54af8f69aaac1e upstream.

Currently the core does not expose scaling_cur_freq for set_policy()
drivers this breaks some userspace monitoring tools.
Change the core to expose this file for all drivers and if the
set_policy() driver supports the get() callback use it to retrieve the
current frequency.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=73741
Signed-off-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

intel_pstate: Set CPU number before accessing MSRs

2014-07-18T13:51:24+00:00

commit 179e8471673ce0249cd4ecda796008f7757e5bad upstream.

Ensure that cpu->cpu is set before writing MSR_IA32_PERF_CTL during CPU
initialization. Otherwise only cpu0 has its P-state set and all other
cores are left with their values unchanged.

In most cases, this is not too serious because the P-states will be set
correctly when the timer function is run.  But when the default governor
is set to performance, the per-CPU current_pstate stays the same forever
and no attempts are made to write the MSRs again.

Signed-off-by: Vincent Minet 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

cpufreq: Makefile: fix compilation for davinci platform

2014-07-18T13:51:21+00:00

commit 5a90af67c2126fe1d04ebccc1f8177e6ca70d3a9 upstream.

Since commtit 8a7b1227e303 (cpufreq: davinci: move cpufreq driver to
drivers/cpufreq) this added dependancy only for CONFIG_ARCH_DAVINCI_DA850
where as davinci_cpufreq_init() call is used by all davinci platform.

This patch fixes following build error:

arch/arm/mach-davinci/built-in.o: In function `davinci_init_late':
:(.init.text+0x928): undefined reference to `davinci_cpufreq_init'
make: *** [vmlinux] Error 1

Fixes: 8a7b1227e303 (cpufreq: davinci: move cpufreq driver to drivers/cpufreq)
Signed-off-by: Lad, Prabhakar 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby