Revert "timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer_target()"

This reverts commit 4a0baf700b470a56486175d85c2acfda97bae3f4.
timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer_target()

Check for current cpu's idleness is already done in implementation of
sched_select_non_idle_cpu() which is called by get_nohz_timer_target(). So, no
need to call idle_cpu() twice, once from sched_select_non_idle_cpu() and once
from timer and hrtimer before calling get_nohz_timer_target().

This patch removes calls to idle_cpu() from timer and hrtimer.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
PHYLIB: queue work on any cpu

Phylib uses workqueues for multiple purposes. There is no real dependency of
scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which isn't
idle to save on power.

By idle cpu (from scheduler's perspective) we mean:
- Current task is idle task
- nr_running == 0
- wake_list is empty

This patch replaces the schedule_work() and schedule_delayed_work() routines
with their queue_[delayed_]work_on_any_cpu() siblings with system_wq as
parameter.

These routines would look for the closest (via scheduling domains) non-idle cpu
(non-idle from schedulers perspective). If the current cpu is not idle or all
cpus are idle, work will be scheduled on local cpu.

Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
mmc: queue work on any cpu

mmc uses workqueues for running mmc_rescan(). There is no real dependency of
scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which isn't
idle to save on power.

By idle cpu (from scheduler's perspective) we mean:
- Current task is idle task
- nr_running == 0
- wake_list is empty

This patch replaces the queue_delayed_work() with
queue_delayed_work_on_any_cpu() siblings.

This routine would look for the closest (via scheduling domains) non-idle cpu
(non-idle from schedulers perspective). If the current cpu is not idle or all
cpus are idle, work will be scheduled on local cpu.

Cc: Chris Ball <cjb@laptop.org>
Cc: linux-mmc@vger.kernel.org
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
block: queue work on any cpu

block layer uses workqueues for multiple purposes. There is no real dependency
of scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which isn't
idle to save on power.

By idle cpu (from scheduler's perspective) we mean:
- Current task is idle task
- nr_running == 0
- wake_list is empty

This patch replaces schedule_work() and queue_[delayed_]work() with
queue_[delayed_]work_on_any_cpu() siblings.

These routines would look for the closest (via scheduling domains) non-idle cpu
(non-idle from schedulers perspective). If the current cpu is not idle or all
cpus are idle, work will be scheduled on local cpu.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
modified for Mako Hybrid kernel

Conflicts:
	block/blk-core.c
fbcon: queue work on any cpu

fbcon uses workqueues and it has no real dependency of scheduling these on the
cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up few times just to
service this work. It would be better if we can schedule it on a cpu which isn't
idle to save on power.

By idle cpu (from scheduler's perspective) we mean:
- Current task is idle task
- nr_running == 0
- wake_list is empty

This patch replaces schedule_work() routine with queue_work_on_any_cpu()
sibling with system_wq as workqueue.

This routine would look for the closest (via scheduling domains) non-idle cpu
(non-idle from schedulers perspective). If the current cpu is not idle or all
cpus are idle, work will be scheduled on local cpu.

Cc: Dave Airlie <airlied@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
block: row: Re-design urgent request notification mechanism

When ROW scheduler reports to the block layer that there is an urgent
request pending, the device driver may decide to stop the transmission
of the current request in order to handle the urgent one. This is done
in order to reduce the latency of an urgent request. For example:
long WRITE may be stopped to handle an urgent READ.

This patch updates the ROW URGENT notification policy to apply with the
below:

- Don't notify URGENT if there is an un-completed URGENT request in driver
- After notifying that URGENT request is present, the next request
  dispatched is the URGENT one.
- At every given moment only 1 request can be marked as URGENT.
  Independent of it's location (driver or scheduler)

Other changes to URGENT policy:
- Only READ queues are allowed to notify of an URGENT request pending.

CR fix:
If a pending urgent request (A) gets merged with another request (B)
A is removed from scheduler queue but is not removed from
rd->pending_urgent_rq.

CRs-Fixed: 453712
Change-Id: I321e8cf58e12a05b82edd2a03f52fcce7bc9a900
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
block: urgent request: remove unnecessary urgent marking

An urgent request is marked by the scheduler in rq->cmd_flags with the
REQ_URGENT flag. There is no need to add an additional marking by
the block layer.

Change-Id: I05d5e9539d2f6c1bfa80240b0671db197a5d3b3f
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: faux123 <reioux@gmail.com>

Conflicts:
	block/test-iosched.c
ASoC: wcd9310: Reset OTHR_RESET_CTR before power down

There is a missing step to clear OTHR_RESET_CTR before power down.
It could cause a glitch and power hit without it. It has to be reset.

original gerrit is https://review-android.quicinc.com/#/c/191312/
This is cherry-pick gerrit by developer to jb_2.5

Change-Id: Id96070352480be6ea412844d4f71765e2df76afe
CRs-fixed: 420142
Signed-off-by: Fred Oh <fred@codeaurora.org>
ASoC: wcd9310: Update compander configuration sequence

Update compander configuration sequence for headphone path
to prevent the concurreny of ANC and compander in addition
to bypass the delay buffer for ANC and class G to avoid the
audio delay change between class G enabled and disable modes.

CRs-fixed: 456565
Change-Id: I561cb878906b9e31d8c1b04c145c533090f80f1f
Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>
Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>
ASoC: wcd9310: Update compander gain implementation

When compander is enabled, PA has no impact on the playback
path. In order to keep the output audio level consistently during
compander enabling and disabling so we have to apply the same
gain/attention in PA to digital gain to compensate the PA gain.

CRs-fixed: 456565
Change-Id: Idf760bac35b25aab419a23ce5803c68831850856
Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>
(cherry picked from commit 39828faf7eb408503d4d1fdd4473642e344496cf)
sysfs: fix race between readdir and lseek Date Wed, 20 Mar 2013 23:25:24 +0800

While readdir() is running, lseek() may set filp->f_pos as zero,
then may leave filp->private_data pointing to one sysfs_dirent
object without holding its reference counter, so the sysfs_dirent
object may be used after free in next readdir().

This patch holds inode->i_mutex to avoid the problem since
the lock is always held in readdir path.

Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
modified for Mako Hybrid kernel from LKML reference

Signed-off-by: faux123 <reioux@gmail.com>
sysfs: handle failure path correctly for readdir() Date Wed, 20 Mar 2013 23:25:25 +0800

In case of 'if (filp->f_pos ==  0 or 1)' of sysfs_readdir(),
the failure from filldir() isn't handled, and the reference counter
of the sysfs_dirent object pointed by filp->private_data will be
released without clearing filp->private_data, so use after free
bug will be triggered later.
This patch returns immeadiately under the situation for fixing the bug,
and it is reasonable to return from readdir() when filldir() fails.

Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
staging: android: ashmem: get_name,set_name not to hold ashmem_mutex Date Wed, 20 Feb 2013 23:41:26 +0530

Problem:
There exists a path in ashmem driver that could lead to acquistion
of mm->mmap_sem, ashmem_mutex in reverse order. This could lead
to deadlock in the system.
For Example, assume that mmap is called on a ashmem region
in the context of a thread say T1.
 sys_mmap_pgoff (1. acquires mm->mmap_sem)
  |
   --> mmap_region
 	|
         ----> ashmem_mmap (2. acquires asmem_mutex)
 Now if there is a context switch after 1 and before 2,
 and if another thread T2 (that shares the mm struct) invokes an
 ioctl say ASHMEM_GET_NAME, this can lead to the following path
ashmem_ioctl
  |
  -->get_name (3. acquires ashmem_mutex)
	|
	---> copy_to_user (4. acquires the mm->mmap_sem)
Note that the copy_to_user could lead to a valid fault if no
physical page is allocated yet for the user address passed.
Now T1 has mmap_sem and is waiting for ashmem_mutex.
and T2 has the ashmem_mutex and is waiting for mmap_sem
Thus leading to deadlock.
Solution:
Do not call copy_to_user or copy_from_user while holding the
ahsmem_mutex. Instead copy this to a local buffer that lives
in the stack while holding this lock. This will maintain data
integrity as well never reverse the lock order.

Testing:
Created a unit test case to reproduce the problem.
Used the same to test this fix on kernel version 3.4.0
Ported the same patch to 3.8

Signed-off-by: Shankar Brahadeeswaran <shankoo77@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
kthread_worker: reorganize to prepare for flush_kthread_work() reimplementation

Make the following two non-functional changes.

* Separate out insert_kthread_work() from queue_kthread_work().

* Relocate struct kthread_flush_work and kthread_flush_work_fn()
  definitions above flush_kthread_work().

v2: Added lockdep_assert_held() in insert_kthread_work() as suggested
    by Andy Walls.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andy Walls <awalls@md.metrocast.net>
kthread_worker: reimplement flush_kthread_work() to allow freeing the work item being executed

kthread_worker provides minimalistic workqueue-like interface for
users which need a dedicated worker thread (e.g. for realtime
priority).  It has basic queue, flush_work, flush_worker operations
which mostly match the workqueue counterparts; however, due to the way
flush_work() is implemented, it has a noticeable difference of not
allowing work items to be freed while being executed.

While the current users of kthread_worker are okay with the current
behavior, the restriction does impede some valid use cases.  Also,
removing this difference isn't difficult and actually makes the code
easier to understand.

This patch reimplements flush_kthread_work() such that it uses a
flush_work item instead of queue/done sequence numbers.

Signed-off-by: Tejun Heo <tj@kernel.org>
cpufreq: conservative: Set MIN_LATENCY_MULTIPLIER to 20

Currently MIN_LATENCY_MULTIPLIER is set defined as 100 and so on a system with
transition latency of 1 ms, the minimum sampling time comes to be around 100 ms.
That is quite big if you want to get better performance for your system.

Redefine MIN_LATENCY_MULTIPLIER to 20 so that we can support 20ms sampling rate
for such platforms.

Signed-off-by: faux123 <reioux@gmail.com>
cpufreq: ondemand: Set MIN_LATENCY_MULTIPLIER to 20

Currently MIN_LATENCY_MULTIPLIER is set defined as 100 and so on a system with
transition latency of 1 ms, the minimum sampling time comes to be around 100 ms.
That is quite big if you want to get better performance for your system.

Redefine MIN_LATENCY_MULTIPLIER to 20 so that we can support 20ms sampling rate
for such platforms.

Signed-off-by: faux123 <reioux@gmail.com>
cpufreq: intellidemand: Set MIN_LATENCY_MULTIPLIER to 20

Currently MIN_LATENCY_MULTIPLIER is set defined as 100 and so on a system with
transition latency of 1 ms, the minimum sampling time comes to be around 100 ms.
That is quite big if you want to get better performance for your system.

Redefine MIN_LATENCY_MULTIPLIER to 20 so that we can support 20ms sampling rate
for such platforms.

Signed-off-by: faux123 <reioux@gmail.com>
Revert "usbnet: ratelimit kevent may have been dropped warnings"

This reverts commit 549a47eb9c31dda4a8d70eaf4507278498af27b3.