removed non existent feature #2
 cfq-iosched: Fix null pointer dereference

NULL pointer dereference can happen in cfq_choose_cfqg()
when there are no cfq groups to select other than the
current serving group. Prevent this by adding a NULL
check before dereferencing.

Unable to handle kernel NULL pointer dereference at virtual address
[<c02502cc>] (cfq_dispatch_requests+0x368/0x8c0) from
[<c0243f30>] (blk_peek_request+0x220/0x25c)
[<c0243f30>] (blk_peek_request+0x220/0x25c) from
[<c0243f74>] (blk_fetch_request+0x8/0x1c)
[<c0243f74>] (blk_fetch_request+0x8/0x1c) from
[<c041cedc>] (mmc_queue_thread+0x58/0x120)
[<c041cedc>] (mmc_queue_thread+0x58/0x120) from
[<c00ad310>] (kthread+0x84/0x90)
[<c00ad310>] (kthread+0x84/0x90) from
[<c000eeac>] (kernel_thread_exit+0x0/0x8)

CRs-Fixed: 416466
Change-Id: I1fab93a4334b53e1d7c5dcc8f93cff174bae0d5e
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
 msm: cpufreq: fix a race between hotplug and cpufreq

When msm_cpufreq_target() is called without holding the policy
semaphore, there is a rare chance that the cpu gets hotplugged in
the acpuclk_set_rate. The probability of this issue increases
when cross-calling is used or using interactive governor which
tries to set all cpu frequencies from a single thread.

Add a hotplug notifier and set the device_suspended flag holding
the suspend mutex, when cpu is going down. This mutex is always
held when frequency changes are done.

Change-Id: Ide3aa6927ad60d2512d63761c51bb15117461250
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
 msm: cpufreq: increase priority of thread that increases frequencies

When the cpufreq governors request for increase in frequency from kworker
threads, there is chance that the kworker thread is cpu starved due to
other high priority threads, leading to undesirable increase in frequency
ramp-up latency. Add the calling thread to SCHED_FIFO policy when
requesting for increase in frequency and restore back to original policy
after ramp-up is completed.

Change-Id: Ie4fa199b7f9087717cb94dfcc2eddea27cc0012b
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
cpufreq: Avoid using smp_processor_id() in preemptible context

Even though this work item runs on only one cpu at a time (due to
queue_work_on()) it is possible for the work item to be preempted
and so use of smp_processor_id() is illegal.

BUG: using smp_processor_id() in preemptible [00000000]
code: kworker/3:1/4162 caller is dbs_refresh_callback+0xc/0x188
[<c00151b0>] (unwind_backtrace+0x0/0x120) from [<c0279058>]
(debug_smp_processor_id+0xbc/0xf0)
[<c0279058>] (debug_smp_processor_id+0xbc/0xf0) from [<c0454b54>]
(dbs_refresh_callback+0xc/0x188)
[<c0454b54>] (dbs_refresh_callback+0xc/0x188) from [<c0087290>]
(process_one_work+0x354/0x648)
[<c0087290>] (process_one_work+0x354/0x648) from [<c0089754>]
(worker_thread+0x1a8/0x2a8)
[<c0089754>] (worker_thread+0x1a8/0x2a8) from [<c008e480>]
(kthread+0x90/0xa0)
[<c008e480>] (kthread+0x90/0xa0) from [<c000f438>]
(kernel_thread_exit+0x0/0x8)

The intent of the code is to determine which CPU this work item
is running on, which we can easily do by passing that information
in a wrapper struct around the work struct. Do this so we avoid
this problem.

Change-Id: I05ca0ff2b3cbaa239930463ea0760e3e9d75145f
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Conflicts:
	drivers/cpufreq/cpufreq_ondemand.c