* 'timers-fixes-for-linus' of git://tesla.tglx.de/git/linux-2.6-tip:
  rtc: twl: Fix registration vs. init order
  rtc: Initialized rtc_time->tm_isdst
  rtc: Fix RTC PIE frequency limit
  rtc: rtc-twl: Remove lockdep related local_irq_enable()
  rtc: rtc-twl: Switch to using threaded irq
  rtc: ep93xx: Fix 'rtc' may be used uninitialized warning
  alarmtimers: Avoid possible denial of service with high freq periodic timers
  alarmtimers: Memset itimerspec passed into alarm_timer_get
  alarmtimers: Avoid possible null pointer traversal

Only register as an RTC device after the hardware has been
successfully initialized.  The RTC class driver will call
back to this driver to read a pending alarm, and other
drivers watching for new devices on the RTC class may
read the RTC time upon registration.  Such access might
occur while the RTC is stopped, prior to clearing
pending alarms, etc.

The new ordering also avoids leaving the platform
device drvdata set to an unregistered struct rtc_device *
on probe errors.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

Even though the Linux kernel does not use the tm_isdst field, it is
exposed as part of the ABI.  This field can accidentally be left
initialized, which is why we currently memset buffers returned to
userland in rtc_read_time.

There is a case however where the field can return garbage from the
stack though when using the RTC_ALM_READ ioctl on the rtc device.  This
ioctl invokes rtc_read_alarm, which is careful to memset the rtc_wkalrm
buffer that is copied to userland, but it then uses a struct copy to
assign to alarm->time given the return value from rtc_ktime_to_tm().

rtc_ktime_to_tm() is implemented by calling rtc_time_to_tm using a
derivative seconds counds from ktime, but rtc_time_to_tm does not assign
a value to ->tm_isdst.  This results in garbage from rtc_ktime_to_tm()'s
frame ending up being copied out to userland as part of the returned
rtc_wkalrm.

Fix this by initializing rtc_time->tm_isdst to 0 in rtc_time_to_tm.

Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

The previous rtc-s3c had two issues related with its IRQ.

1. Users cannot open rtc multiple times because an open operation
   calls request_irq on the same IRQ.  (e.g., two user processes wants to
   open and read RTC time from rtc-s3c at the same time)

2. If alarm is set and no one has the rtc opened with filesystem
   (either the alarm is set by kernel/boot-loader or user set an alarm and
   closed rtc dev file), the pending bit is not cleared and no further
   interrupt is invoked.  When the alarm is used by the system itself such
   as a resume from suspend-to-RAM or other Low-power modes/idle, this is
   a critical issue.

This patch mitigates these issues by calling request_irq at probe and
free_irq at remove.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RTC-S3C used to print out debug messages incorrectly.  This patch
corrects incorrect outputs.  (undecoded bcd numbers, incorrectly decoded
register values)

This patch affects the pr-debug messages only.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rtc: Limit RTC PIE frequency
  rtc: Fix hrtimer deadlock
  rtc: Handle errors correctly in rtc_irq_set_state()

Fixup trivial conflicts in drivers/rtc/interface.c due to slightly
trivially versions of the same patch coming in two different ways.

Thomas earlier submitted a fix to limit the RTC PIE freq, but
picked 5000Hz out of the air. Willy noticed that we should
instead use the 8192Hz max from the rtc man documentation.

Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

Now that the irq is properly threaded (due to it needing i2c access)
we should also remove the local_irq_enable() call in twl_rtc_interrupt.
Testing this with Pandaboard, the RTC is still working.

[Reworked commit message -jstultz]
Signed-off-by: John Stultz <john.stultz@linaro.org>

The driver is accessing to i2c bus in interrupt handler.
Therefore, it should use threaded irq.

Signed-off-by: Ilkka Koskinen <ilkka.koskinen@nokia.com>
Acked-by: Balaji T K <balajitk@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

commit 92d921c5d "rtc: ep93xx: Initialize drvdata before registering device"
ensures the drvdata is initialized prior to registering the rtc device.
But it set the drvdata to an uninitialized pointer.
Thus calling platform_get_drvdata in ep93xx_rtc_remove does not get correct address.

This patch fixes below warning by adding struct rtc_device *rtc to struct ep93xx_rtc.
Then set platform drvdata to ep93xx_rtc instead of rtc.

  CC      drivers/rtc/rtc-ep93xx.o
drivers/rtc/rtc-ep93xx.c: In function 'ep93xx_rtc_probe':
drivers/rtc/rtc-ep93xx.c:154: warning: 'rtc' may be used uninitialized in this function

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>