cpufreq: Retain only online cpus in managed_policy->cpus

cpufreq's handling of cpu online event can incorrectly initialize
managed_policy->cpus to include offline cpus. This causes cpufreq
governors to include offline cpus in their idle time computation, which
causes frequency to shoot up beyond normal levels (on systems where 2 or
more cpus need to be synchronized wrt frequency change).

This frequency shootup was not seen prior to commit 21111be8 which
changed idle time accounting for offline cpus. Prior to commit 21111be8,
idle time statistics for offline cpus would include their offline time
as well. Post commit 21111be8, offline time is not included in a cpu's
idle time statistics.

As a result, ondemand (or other cpufreq) governors would see unchanged
idle time for offline cpus, causing them to interpret those (offline)
cpus as 100% busy, which is wrong.

This patch fixes the issue by modifying cpufreq's hotplug handling to
retain only online cpus in managed_policy->cpus field. cpufreq governors
would then skip such offline cpus from idle time calculations.

Change-Id: Id2eba8c0ec3367609369b2e42a4e1386ff2e7ab5
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
msm: cpufreq: Only apply driver limits for scaling_min/max_freq writes

When new values are written to scaling_min/max_freq sysfs files, the
current code applies all the limits imposed by various ADJUST and
INCOMPATIBLE notifiers handlers before storing them.

When the ADJUST and/or INCOMPATIBLE notifiers change their limits
frequently, this behavior makes it almost impossible for a
user/userspace process to store the scaling_min/max_freq limits
that go beyond the instantaneous limits imposed by the notifiers.
Since these sysfs nodes are typically meant to set limits that need
to be enforced for the foreseeable future, this is not a very user
friendly behavior.

So, change the behavior to only apply limits that are enforced by
the cpufreq driver. Typically, these are just the absolute limits
of the HW and don't change very often.

Change-Id: I1ccfaa2d1ee4ea595f882485d359dbdb407a0176
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>
cpufreq: Save user policy min/max instead of policy min/max during hotplug

When a CPU is hotplugged off, various fields of the policy are saved so
that they can be restored when the CPU is hotplugged back in.

The existing code saves the policy min/max field during hotplug remove and
restores it into user policy min/max during hotplug add. This results in
the loss of the user policy min/max values across a hotplug remove/add.

Fix it by saving the user policy min/max instead of policy min/max during
hotplug remove. During a hotplug add, after user policy min/max is
restored, the policy min/max is already recomputed. So, there's no risk of
going beyound any limits imposed by the CPUFREQ_ADJUST/INCOMPATIBLE
notifiers.

Change-Id: Ib8e09fa324c1f80f095c5754b5dcf2685e8e4a66
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
msm: cpufreq: Initialize cpufreq driver early at boot

MSM cpufreq driver registering with the CPUFreq framework during
late_initcall() may cause the device to be available a few seconds after
the clock driver is ready for changing frequency. This could be bad for
boot and/or thermal performance, since the cpu will continue to boot at
whatever frequency the bootloaders set it to.

Initialize cpufreq driver as part of device_initcalL() but only after
all the clock drivers have had a chance to initialize their devices.

Change-Id: Iaa4867108f59a368ee5b511d35ea2e8e219d39d3
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
msm: cpufreq: Always update frequency limits when core is online

Remove condition in msm_cpufreq_init() so that when cpu is set to
online, it will call set_cpu_freq() and update the frequency limits.

CRs-Fixed: 462816
Change-Id: I40ac33c9cb4b42590a83f9d61b74f23379f5642e
Signed-off-by: Jennifer Liu <chihning@codeaurora.org>
msm: cpufreq: Configure WQ for higer priority

When the workqueue runs at a lower priority, it gets starved by higher
priority threads. Bump the WQ priority to high to ensure cpufreq work
queue gets a fair scheduling chance

Change-Id: I9e994da94a347dceb884e72ec3dd3da468a4471d
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
msm: cpufreq: Relax constraints on "msm-cpufreq" workqueue

This workqueue is not used in memory reclaim paths, so the
WQ_MEM_RECLAIM flag is not needed. Additionally, there is no
need to restrict the queue to having one in-flight work item.
Remove these constraints.

Change-Id: I9edde40917d3ec885ce061133de20680634321d0
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
msm: cpufreq: Ensure cpufreq change happens on corresponding CPU

Checking the cpus_allowed mask of the current thread before changing the
frequency doesn't guarantee that the rest of the execution will continue on
the same CPU. The only way to guarantee this is to schedule a work on the
specific CPU and also prevent hotplug  of that CPU (already done by
existing code).

Change-Id: I51a02fcc777a47d3c16f2d83c47e96f2c59f7ae6
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Revert "msm: mdp: Update sync pt. behaviour"

This reverts commit c44dde948554234c0766563029e3e64c9b91def7.
Revert "msm: mdp: Change msmfb kworker to kthread"

This reverts commit 9a619e36cbfdc60a739625580f7ecbcd28021902.

Change-Id: I28a30970b56709ffe504a7fdba1d54d2107543ed
Revert "msm: display: command mode panel release fence"

This reverts commit 5ffcd5a84d220c6bd7672a4fe2e0e41151eb5765.

Change-Id: I5cea0ba38b927f68ca7250774fafe2e5bc797232
msm8930: display: Use Samsung's bandwidth values from kk kernel

 * Might help with underruns, especially on lt02 and melius

Change-Id: I4af1b416434ce32c2c40e2b287facabb9c9877eb