Re: [PATCH] time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons

[Feng Tang <feng.tang@intel.com>]

On Wed, Apr 24, 2013 at 11:32:56AM -0700, John Stultz wrote:
> Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config,
> which enables some minor compile time optimization to avoid
> uncessary code in mostly the suspend/resume path could cause
> problems for userland.
> 
> In particular, the dependency for RTC_HCTOSYS on
> !ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time
> twice and simplifies suspend/resume, has the side effect
> of causing the /sys/class/rtc/rtcN/hctosys flag to always be
> zero, and this flag is commonly used by udev to setup the
> /dev/rtc symlink to /dev/rtcN, which can cause pain for
> older applications.
> 
> While the udev rules could use some work to be less fragile,
> breaking userland should strongly be avoided. Additionally
> the compile time optimizations are fairly minor, and the code
> being optimized is likely to be reworked in the future, so
> lets revert this change.
> 
> I suspect this will miss 3.9-final, so marking it for 3.9-stable.

thanks

Acked-by: Feng Tang <feng.tang@intel.com>