ARM: smp: BUG() if smp_send_reschedule() is called for an offline cpu

Sending an IPI_RESCHEDULE to an offline CPU is incorrect and potentially
bad for both power and stability. On some sub-architectures such as MSM,
if a power-collapsed CPU is unexpectedly woken up by an IPI, it will be
begin executing without the preparations that would normally happen as
part of CPU_UP_PREPARE. If clocks, voltage regulators, or other hardware
configuration are not performed, the booting CPU may cause general
instability or (at best) poor power performance since the CPU would be
powered up but not utilized.

One common cause for such issues is misuse of add_timer_on() or APIs
such as queue_work_on() which call it. If proper precautions are not
taken to block hotplug while these APIs are called then a race may
result in IPIs being sent to CPUs that are already offline.

This same argument could be applied to other IPIs (with the exception
of IPI_WAKEUP), but the others are already restricted to only online
CPUs by existing mechanisms, so an explicit assertion is not useful.

Change-Id: I437db112e7e2fa7c0635e4e97e265692621944f1
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
msm: smd_tty: Fix client notification issue in suspend state

SMD_TTY driver holds a wakeup source for 500ms to provide enough time
to notify the user client waiting for data. However, when system is in
suspend state the 500ms timer may not be sufficient to notify the
user clients because in some cases system resume of devices and tasks
is taking more time and this causes delay in client notification.

Register for PM_SUSPEND_PREPARE and PM_POST_SUSPEND events to track
system suspend and resume state and then notify the clients after system
resume completes.

CRs-Fixed: 613589
Change-Id: Iffb2ecb1c58f46e0c4a745cdcce2fb717ea2ece8
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
ion: Add missing unlock on error path

A mutex_unlock was missing for the alloc_lock on an error
path. Add it.

Change-Id: If88b72fbc2fd18504347b784d5daa2bc9170c55f
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
(cherry picked from commit 76d17e36bbb9f1a3acde26e02cfa4ee20903f4f5)