cpufreq: reset ondemand to CAF at msm-3.6.38

Change-Id: I167087e76b37ae9b93bd4fda8713a33b791fb71e
cpufreq: Fix input handler crash

When input handler is running on a CPU not in ondemand
governor, skip making CPU frequency changes.

CRs-Fixed: 299451
Signed-off-by: David Ng <dave@codeaurora.org>
cpufreq : Fix crash input event handler on governor switch

When an input event and CPU1 hotplug occurs at the same
time, a race condition can happen between cpufreq and
cpu hotplug resulting in a kernel panic.
When a hotplug operation is underway on CPU1,
__cpufreq_remove_dev is called. __cpufreq_remove_dev gets
the lock, proceeds to free the policy info of the current
governor and calls the ondemand governor with a STOP event.
If an input event occurs around the same time, it waits
for __cpufreq_remove_dev to release the lock. Meanwhile,
the ondemand governor clears some of its settings, but
fails to clear its local current policy. As soon as the
input event handler acquires the lock, it now uses the
invalid ondemand current policy handle to make frequency
changes. This results in a kernel panic.

Skip making frequency changes if this condition happens.

CRs-fixed: 327622,319348
Change-Id: I78227352fc66cc3ec5ab095c45eda76a92d1ba46
Signed-off-by: Anitha Anand <anithas@codeaurora.org>
cpufreq: Extend ondemand powersave_bias for negative range

Original ondemand powersave_bias parameter allows value
range from 0 (no powersave) to 1000 (100% reduction in
calculated CPU frequency).  This change extends powersave_bias
into the negative range (-1 to -1000) to allow a corresponding
boost to CPU frequency.  When set at either limit (-1000 or
1000), ondemand timer is cancelled as periodic load
sampling at sampling_rate is not necessary.

Change-Id: I2ee05729ceec20c2e2a4c6d9ca05cecd16ab161a
Signed-off-by: David Ng <dave@codeaurora.org>
cpufreq: make the "scaling_cur_freq" sysfs entry pollable

Wakeup userspace poll on change of cpu frequency. The userspace
may then take action to change the power/performance
characteristics of the device.

Change-Id: I3030b22084fe7e0143b978a198ddcc579e7d6e83
Signed-off-by: Amar Singhal <asinghal@codeaurora.org>
msm: cpufreq: Fix store_powersave_bias to account for sync' CPUs.

Current code assumes that all online CPUs runs their own timers to
collect CPU samples for demand based switching (dbs). But in case of
synchronous CPUs, ondemand governor registers only one timer at init
time because both CPUs are accounted in the same timer call. Hence
trying to restart/cancel dbs timers for all online CPUs is not legal
for these CPUs. This change fixes above function to restart/cancel
timers only once for group of synchronous CPUs.

Change-Id: I23f1697783a65f125679a07a076620e8fa5e62d5
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
msm: cpufreq: Fix the race between dbs_refresh and hotplug.

The demand based switching responds to input events and schedules
work items on all online cpus to increase the frequency. This will
call the dbs_refresh_callback on respective cpu. If this work item
kicks in while cpu1 is progressing its way through cpufreq_add_dev,
there is a chance that work item grabs the cpu_policy_rwsem of cpu1
and relases that of cpu0, when add device is working through releas-
ing lock of cpu1 and reaquiring that of cpu0. This is locking out
cpu1 when it tries to come up online next time. The fix is hold the
hot plug lock while processing refresh work items.

CRs-Fixed: 362444
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
(cherry picked from commit a3e04d8b2b5d996a75fc89a14d7fc1a0efe03e73)

Change-Id: I09cfcc03eb7a76ca1baa69a03228848eef989908
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
cpufreq: Make the "scaling_governor" sysfs node pollable

A userspace module programs different qos-rules depending on the
governor running in the system. Make the governor node
pollable, so that the userspace module can be triggered when
the value of the governor changes.

change-Id: Ic89c77c7d16b0f8954d59a211612e9a8e98a2c28
Signed-off-by: Amar Singhal <asinghal@codeaurora.org>
(cherry picked from commit 37d0b028bf4c8f877f7c0137ea430bd2a73c9461)

Signed-off-by: Dhivya Subramanian <dthiru@codeaurora.org>
cpufreq: Add cpu utilization statistics to aid decisions made by userspace.

Understanding system load as seen by cpufreq can help userspace
algorithms make better decisions to improve system responsiveness.
One such example would be the MP decision algorithm which mines
various system info to make decisions on hotplugging in/out
the additional cores.

Signed-off-by: Anitha Anand <anithas@codeaurora.org>
(cherry picked from commit cbeef6aafc4964c4a6cfafd26b23eaccd40804b4)

Change-Id: I8a5fb95380af898076fe0e246fb21e3aa48b33b1
Signed-off-by: Shruthi Krishna <skrish@codeaurora.org>
cpufreq: fix utilization statistics for sync cpus

If the cpus are using related_cpus policy, then the
current implementaion will overwrite the the calculated
load for every iteration in the for loop. Hence, mpdecision
will read incorrect value, if the cores are using related
cpus policy. With this change mpdecision will read the
sum of the loads of all cpu's, if related cpu policy is
used.

Change-Id: I242c8fe39fd75dc3e48750a5b78a5d218b536ddd
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
Signed-off-by: Shruthi Krishna <skrish@codeaurora.org>
cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch

Running one program that continuously hotplugs and replugs a cpu
concurrently with another program that continuously writes to the
scaling_set_speed node eventually deadlocks with:

=============================================
[ INFO: possible recursive locking detected ]
3.4.0 #37 Tainted: G        W
---------------------------------------------
filemonkey/122 is trying to acquire lock:
 (s_active#13){++++.+}, at: [<c01a3d28>] sysfs_remove_dir+0x9c/0xb4

but task is already holding lock:
 (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(s_active#13);
  lock(s_active#13);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by filemonkey/122:
 #0:  (&buffer->mutex){+.+.+.}, at: [<c01a2230>] sysfs_write_file+0x28/0x140
 #1:  (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

stack backtrace:
[<c0014fcc>] (unwind_backtrace+0x0/0x120) from [<c00ca600>] (validate_chain+0x6f8/0x1054)
[<c00ca600>] (validate_chain+0x6f8/0x1054) from [<c00cb778>] (__lock_acquire+0x81c/0x8d8)
[<c00cb778>] (__lock_acquire+0x81c/0x8d8) from [<c00cb9c0>] (lock_acquire+0x18c/0x1e8)
[<c00cb9c0>] (lock_acquire+0x18c/0x1e8) from [<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180)
[<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180) from [<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4)
[<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4) from [<c02d0e5c>] (kobject_del+0x10/0x38)
[<c02d0e5c>] (kobject_del+0x10/0x38) from [<c02d0f74>] (kobject_release+0xf0/0x194)
[<c02d0f74>] (kobject_release+0xf0/0x194) from [<c0565a98>] (cpufreq_cpu_put+0xc/0x24)
[<c0565a98>] (cpufreq_cpu_put+0xc/0x24) from [<c05683f0>] (store+0x6c/0x74)
[<c05683f0>] (store+0x6c/0x74) from [<c01a2314>] (sysfs_write_file+0x10c/0x140)
[<c01a2314>] (sysfs_write_file+0x10c/0x140) from [<c014af44>] (vfs_write+0xb0/0x128)
[<c014af44>] (vfs_write+0xb0/0x128) from [<c014b06c>] (sys_write+0x3c/0x68)
[<c014b06c>] (sys_write+0x3c/0x68) from [<c000e0e0>] (ret_fast_syscall+0x0/0x3c)

This is because store() in cpufreq.c indirectly grabs a kobject
with kobject_get() and is the last one to call kobject_put()
indirectly via cpufreq_cpu_put().

Fix this deadlock by introducing two new functions,
cpufreq_cpu_get_sysfs() and cpufreq_cpu_put_sysfs() which do the
same thing as cpufreq_cpu_{get,put}() but don't grab the kobject.

CRs-fixed: 366560
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
(cherry picked from commit f82ef51be26b44b83d86afa56b3cd9c743023470)

Change-Id: Ibde742d55fd4f770c402b8abce31ec266c57007d
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
cpufreq: Add a boostpulse interface to ondemand

For applications that require a one-shot increase in frequency,
the boostpulse interface would help to scale to max for the time
specified in boostime. This helps applications that currently
increases scaling_min_freq and resets later after a fixed duration.
Instead of changing scaling_min_freq applications can directly write
to boostpulse and governer resets during regular timer after the time
expires.

Change-Id: Ie5f490ff06b41364aa76dd468573433495da28a4
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
cpufreq: notify avg load for short sampling_rate

If the sampling rate is less than 50ms reporting
the actual load may lead to poor decision making
at user space. So, for sampling rates less than 50ms
report the average of load across two samples.

Change-Id: I0d1cf00801732bee8e4380158d7e892758226594
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
cpufreq: boost the sampling rate on touch event

For better Ux responsiveness ondemand sampling rate
needs to be 20ms. But, a 20ms sampling rate increases power
consumption. So, boost the sampling rate to 20ms on every
touch event for 2.5 ms and later reset to default rate.
Also, change sampling down factor proportional to the
sampling rate.

Change-Id: I111b1cf3b8ed133347149afc34d329d0384ecfcb
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>