cpufreq: ondemand: Fix store_powersave_bias() race with hotplug

store_powersave_bias() assumes that CPUs will not be taken offline or
brought online while executing its for_each_online_cpu() loops. Fix
this race by blocking hotplug while executing in these loop.

CRs-Fixed: 494407
Change-Id: I0d5520444ec21a8d9b12fb73c06ac8442449fa85
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
cpufreq: ondemand: Fix locking in store_powersave_bias

store_powersave_bias() assumes that dbs_info->cur_policy will
not change while it is executing. If it does, memory corruption
can potentially result. Fix this by acquiring the dbs_lock.

Most noticeably, this resolves timer-related list corruptions
encountered when queue_delayed_work_on() is called from within
store_powersave_bias() while a CPU is being hotplugged in and
out.

CRs-Fixed: 494407
Change-Id: I0fd5cbef6834545274cad9481e574ec50b37b871
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
cpufreq: ondemand: Boost CPU frequency only for touch input

Originally CPU frequency were boosted for any input event.
In some case, sensor sends a lot of input event, which
keep CPU in high frequency.  CPU frequency only need to
be boosted when real user interaction happens.

Change-Id: Ia3ad755b98d8363a17729926610b5dd6f0075288
CR-Fixed: 507519
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
cpufreq: ondemand: add input_boost interface

Currently Ondemand governor handles any input event
like touch by scaling the CPU frequency to maximum
available on the target.

This change adds a new sysfs interface "input_boost"
whereby the CPU will scale to this frequency on input events.
The value of this sysfs is user defined so input events
can now be handled by scaling the CPU to lower frequencies
than target max.

Change-Id: I5428fd8797c9984b17a66b01a44557f2160e8b68
Signed-off-by: Dilip Gudlur <dgudlur@codeaurora.org>