hrtimer: Consider preemption when migrating hrtimer cpu_bases

When switching to a new cpu_base in switch_hrtimer_base(), we
briefly enable preemption by unlocking the cpu_base lock in two
places. During this interval it's possible for the running thread
to be swapped to a different CPU.

Consider the following example:

CPU #0                                 CPU #1
----                                   ----
hrtimer_start()                        ...
 lock_hrtimer_base()
 switch_hrtimer_base()
  this_cpu = 0;
  target_cpu_base = 0;
  raw_spin_unlock(&cpu_base->lock)
<migrate to CPU 1>
...                                    this_cpu == 0
                                       cpu == this_cpu
                                       timer->base = CPU #0
                                       timer->base != LOCAL_CPU

Since the cached this_cpu is no longer accurate, we'll skip the
hrtimer_check_target() check. Once we eventually go to program
the hardware, we'll decide not to do so since it knows the real
CPU that we're running on is not the same as the chosen base. As
a consequence, we may end up missing the hrtimer's deadline.

Fix this by updating the local CPU number each time we retake a
cpu_base lock in switch_hrtimer_base().

Another possibility is to disable preemption across the whole of
switch_hrtimer_base.  This looks suboptimal since preemption
would be disabled while waiting for lock(s).

Change-Id: I3f76d528ab2288ef5f950f4d048e7f3fa6cf1228
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
hrtimer: Prevent enqueue of hrtimer on dead CPU

When switching the hrtimer cpu_base, we briefly allow for
preemption to become enabled by unlocking the cpu_base lock.
During this time, the CPU corresponding to the new cpu_base
that was selected may in fact go offline. In this scenario, the
hrtimer is enqueued to a CPU that's not online, and therefore
it never fires.

As an example, consider this example:

CPU #0                          CPU #1
----                            ----
...                             hrtimer_start()
                                 lock_hrtimer_base()
                                 switch_hrtimer_base()
                                  cpu = hrtimer_get_target() -> 1
                                  spin_unlock(&cpu_base->lock)
                                <migrate thread to CPU #0>
                                <offline>
spin_lock(&new_base->lock)
this_cpu = 0
cpu != this_cpu
enqueue_hrtimer(cpu_base #1)

To prevent this scenario, verify that the CPU corresponding to
the new cpu_base is indeed online before selecting it in
hrtimer_switch_base(). If it's not online, fallback to using the
base of the current CPU.

Change-Id: I6359cb299ba7e08abf25d3360fcdd925b4c03b69
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
msm: otg: Handle otg interrupts only if they are enabled

without this check driver tries to handles otgsc session valid
interrupt when interrupt source is any other otg interrupt.

Change-Id: Ic32ab9784509ddbfbb985f7990e87e221ff0a1b1
Signed-off-by: Vamsi Krishna <vskrishn@codeaurora.org>
USB: msm_otg: Notify the charger type early

The current code notify the charger type to power supply driver
only after the amount of avaialble current is determined.  If
we are attached to Host PC, this is delayed till host sends
set config request.  Instead notify the charger type once the
charger is determined.

CRs-Fixed: 441014
Change-Id: Ieb126ae8106ed1b0433c3d756d473e37cb55cdca
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Merge "Enable RTC write" into cm-10.1

Change-Id: I302212edb9e4ace5cbf1c7fdf608725688589534
mmc: core: Fix possbile memory leak

Fix possible memory leak detected by kmemleak:

unreferenced object 0xc0f80f00 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937508 (age 82.980s)
  hex dump (first 32 bytes):
    6d 6d 63 30 5f 64 65 74 65 63 74 00 72 79 2e 68  mmc0_detect.ry.h
    00 07 00 00 68 77 63 61 70 2e 68 00 02 00 00 70  ....hwcap.h....p
  backtrace:
    [<c010a1fc>] __kmalloc+0x164/0x220
    [<c01e1630>] kvasprintf+0x38/0x58
    [<c01e1668>] kasprintf+0x18/0x24
    [<c02fcf60>] mmc_alloc_host+0x114/0x1b4
    [<c0311c84>] msmsdcc_probe+0xc14/0x1fd8
    [<c022b40c>] platform_drv_probe+0x14/0x18
    [<c022a144>] driver_probe_device+0x144/0x334
    [<c022a394>] __driver_attach+0x60/0x84
    [<c022884c>] bus_for_each_dev+0x4c/0x78
    [<c0229720>] bus_add_driver+0xd0/0x250
    [<c022a884>] driver_register+0x9c/0x128
    [<c00086bc>] do_one_initcall+0x90/0x160
    [<c06d1904>] kernel_init+0xe8/0x1a4
    [<c000ee4c>] kernel_thread_exit+0x0/0x8
    [<ffffffff>] 0xffffffff

Change-Id: I3b29d71463af849a072cabbe56637adf6db6d0da
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
random: remove warning
random: prevent add_input from doing anything
bcmdhd: tweaked wakelocks a bit
mmc: decrease wakelock timeout
drivers: mmc: disable CRC.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
hrtimer: Don't reinitialize a cpu_base's lock on CPU_UP

The current code makes the assumption that a cpu_base lock cannot
be held if a CPU is offline, which is tragically wrong.

If a hrtimer is not queued, then it will not be migrated by
migrate_hrtimers() when a CPU is offlined. Therefore, the
hrtimer's cpu_base may still point to a CPU which has
subsequently gone offline if the timer wasn't enqueued at the
time the CPU went down.

Normally this wouldn't be a problem, but a cpu_base's lock is
blindly reinitialized each time a CPU is brought up. If a CPU is
brought online during the period that another thread is
performing a hrtimer operation on a stale hrtimer, then the lock
will be reinitialized under its feet, and a SPIN_BUG() like the
following will be observed:

 [  448.212369] BUG: spinlock already unlocked on CPU#3,
 swapper/3/0
[  448.217368]  lock: 0xc47b1a40, .magic: dead4ead, .owner:
swapper/3/0, .owner_cpu: -1
[  448.217398] [<c0014398>] (unwind_backtrace+0x0/0x120) from
[<c0269ab0>] (do_raw_spin_unlock+0x44/0xdc)
[  448.217419] [<c0269ab0>] (do_raw_spin_unlock+0x44/0xdc) from
[<c071bbb0>] (_raw_spin_unlock_irqrestore+0xc/0x38)
[  448.217438] [<c071bbb0>]
(_raw_spin_unlock_irqrestore+0xc/0x38) from [<c00aa498>]
(hrtimer_try_to_cancel+0xf8/0x10c)
[  448.217455] [<c00aa498>] (hrtimer_try_to_cancel+0xf8/0x10c)
from [<c00aa4bc>] (hrtimer_cancel+0x10/0x20)
[  448.217475] [<c00aa4bc>] (hrtimer_cancel+0x10/0x20) from
[<c00e6934>] (rcu_idle_exit_common+0x5c/0xe0)
[  448.217494] [<c00e6934>] (rcu_idle_exit_common+0x5c/0xe0) from
[<c00e6ae8>] (rcu_idle_exit+0x9c/0xb4)
[  448.217514] [<c00e6ae8>] (rcu_idle_exit+0x9c/0xb4) from
[<c000f2dc>] (cpu_idle+0x98/0xf0)
[  448.217529] [<c000f2dc>] (cpu_idle+0x98/0xf0) from
[<000081ac>] (0x81ac)

CRs-Fixed: 460670
Change-Id: I588f6a864054abe6d4c249aad815c6d2f5a54077
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
kthread: Implement park/unpark facility

To avoid the full teardown/setup of per cpu kthreads in the case of
cpu hot(un)plug, provide a facility which allows to put the kthread
into a park position and unpark it when the cpu comes online again.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120716103948.236618824@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
input: evdev: Move wake_lock_destroy call

Calling wake_lock_destroy from inside a spinlock
protected region (or, in general, from atomic context)
leads to a 'scheduling while atomic bug' because the
internal wakeup source deletion logic calls
synchronize_rcu, which can sleep. Moreover,
since the interal lists are already protected with
RCUs and spinlocks, putting the wake_lock_destroy
call in a spinlock is redundant.

Change-Id: I10a2239b664a5f43e54495f24fe588fb09282305
Signed-off-by: Anurag Singh <anursing@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
power: decrease the amount of time the device waits after entering low power mode to freeze processes. Testing phase at the moment.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
ARM: Allow arm_memblock_steal() to remove memory from any RAM region

Allow arm_memblock_steal() to remove memory from any RAM region,
including highmem areas.  This allows memory to be stolen from the
very top of declared memory, including highmem areas, rather than
our precious lowmem.

Change-Id: Ib4dbc4e7bc34d402134d96db5ed8118eaffa0245
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Git-commit: 7ac68a4c1de6aac5b0bb231fe6d8505ebe5686d9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>