RTC fixes for 3.1

Hey Thomas,
So while your analysis obviously pointed out the problem, just to be
sure I took your rtc patches and ran them through the stress test that I was using to reproduce the issue Ben reported, and they've lasted for over six hours now without issue (usually I could trigger the lockup in 30 minutes to an hour).

Thanks again for the narrowing down the issue and the patches to fix it!

I've reworked some of the commit logs and also refined the PIE hrtimer freq limit (using Willy's suggestion of the ~8khz max value from the man page). The patches are available in the git repository at:

git://git.linaro.org/people/jstultz/linux.git fortglx/3.1/tip/timers/rtc

Thomas Gleixner (3):
rtc: Handle errors correctly in rtc_irq_set_state()
rtc: Fix hrtimer deadlock
rtc: Limit RTC PIE frequency

 drivers/rtc/interface.c |   55 ++++++++++++++++++++++++++++++++--------------
 include/linux/rtc.h     |    3 ++
 2 files changed, 41 insertions(+), 17 deletions(-)