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authorJohn Stultz <john.stultz@linaro.org>2013-04-24 11:32:56 -0700
committerThomas Gleixner <tglx@linutronix.de>2013-05-14 20:54:06 +0200
commitb4f711ee03d28f776fd2324fd0bd999cc428e4d2 (patch)
tree8d8b659c2514648be0bfe51f0de65110da008f22 /drivers/rtc
parent42a5cf46cd56f46267d2a9fcf2655f4078cd3042 (diff)
downloadlinux-b4f711ee03d28f776fd2324fd0bd999cc428e4d2.tar.bz2
time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
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. Reported-by: Kay Sievers <kay@vrfy.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: stable <stable@vger.kernel.org> #3.9 Cc: Feng Tang <feng.tang@intel.com> Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/Kconfig2
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0c81915b1997..b9838130a7b0 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -20,7 +20,6 @@ if RTC_CLASS
config RTC_HCTOSYS
bool "Set system time from RTC on startup and resume"
default y
- depends on !ALWAYS_USE_PERSISTENT_CLOCK
help
If you say yes here, the system time (wall clock) will be set using
the value read from a specified RTC device. This is useful to avoid
@@ -29,7 +28,6 @@ config RTC_HCTOSYS
config RTC_SYSTOHC
bool "Set the RTC time based on NTP synchronization"
default y
- depends on !ALWAYS_USE_PERSISTENT_CLOCK
help
If you say yes here, the system time (wall clock) will be stored
in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11