cpuidle: remove cross-cpu IPI by new latency request.

when drivers request new latency requirement, it's not necessary to
immediately wake up another cpu by sending cross-cpu IPI, we can consider
the new latency to be taken into effect after next wakeup from idle,
this can save the unnecessary wakeup cost, and reduce the risk that
drivers may request latency in irq disabled context.

[<c08e0cc0>] (__irq_svc+0x40/0x70) from [<c00e801c>] (smp_call_function_single+0x16c/0x240)
[<c00e801c>] (smp_call_function_single+0x16c/0x240) from [<c00e855c>] (smp_call_function+0x40/0x6c)
[<c00e855c>] (smp_call_function+0x40/0x6c) from [<c0601c9c>] (cpuidle_latency_notify+0x18/0x20)
[<c0601c9c>] (cpuidle_latency_notify+0x18/0x20) from [<c00b7c28>] (blocking_notifier_call_chain+0x74/0x94)
[<c00b7c28>] (blocking_notifier_call_chain+0x74/0x94) from [<c00d563c>] (pm_qos_update_target+0xe0/0x128)
[<c00d563c>] (pm_qos_update_target+0xe0/0x128) from [<c0620d3c>] (msmsdcc_enable+0xac/0x158)
[<c0620d3c>] (msmsdcc_enable+0xac/0x158) from [<c06050e0>] (mmc_try_claim_host+0xb0/0xb8)
[<c06050e0>] (mmc_try_claim_host+0xb0/0xb8) from [<c0605318>] (mmc_start_bkops.part.15+0x50/0x2f4)
[<c0605318>] (mmc_start_bkops.part.15+0x50/0x2f4) from [<c00ab768>] (process_one_work+0x124/0x55c)
[<c00ab768>] (process_one_work+0x124/0x55c) from [<c00abfc8>] (worker_thread+0x178/0x45c)
[<c00abfc8>] (worker_thread+0x178/0x45c) from [<c00b0b24>] (kthread+0x84/0x90)
[<c00b0b24>] (kthread+0x84/0x90) from [<c000fdd4>] (kernel_thread_exit+0x0/0x8)
Disabling lock debugging due to kernel taint
coresight-etb coresight-etb.0: ETB aborted
Kernel panic - not syncing: softlockup: hung tasks

Signed-off-by: Guojian Chen <a21757@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/532702
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Reviewed-by: Christopher Fries <qcf001@motorola.com>
Reviewed-by: David Ding <dding@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpuidle: remove unused hrtimer_peek_ahead_timers() call

  Author: Arjan van de Ven <arjan@linux.intel.com>
  Date:   Sun Nov 9 12:45:10 2008 -0800

     regression: disable timer peek-ahead for 2.6.28

     It's showing up as regressions; disabling it very likely just papers
     over an underlying issue, but time is running out for 2.6.28, lets get
     back to this for 2.6.29

 Many years has passed since 2008, so it seems ok to remove whole `#if 0' block.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Trinabh Gupta <g.trinabh@gmail.com>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / cpuidle: Add driver reference counter

Add a reference counter for the cpuidle driver, so that it can't
be unregistered when it is in use.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>