From: john stultz Date: Thu, 5 May 2011 01:16:50 +0000 (-0700) Subject: clocksource: Install completely before selecting X-Git-Tag: v2.6.35.14~169 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5284561b0290f09e1c6c99a18b4bc6f39b5ca4d1;p=thirdparty%2Fkernel%2Fstable.git clocksource: Install completely before selecting commit e05b2efb82596905ebfe88e8612ee81dec9b6592 upstream. Christian Hoffmann reported that the command line clocksource override with acpi_pm timer fails: Kernel command line: clocksource=acpi_pm hpet clockevent registered Switching to clocksource hpet Override clocksource acpi_pm is not HRT compatible. Cannot switch while in HRT/NOHZ mode. The watchdog code is what enables CLOCK_SOURCE_VALID_FOR_HRES, but we actually end up selecting the clocksource before we enqueue it into the watchdog list, so that's why we see the warning and fail to switch to acpi_pm timer as requested. That's particularly bad when we want to debug timekeeping related problems in early boot. Put the selection call last. Reported-by: Christian Hoffmann Signed-off-by: John Stultz Signed-off-by: Andi Kleen Link: http://lkml.kernel.org/r/%3C1304558210.2943.24.camel%40work-vm%3E Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index f08e99c1d5617..c232eebbf7ee3 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -665,8 +665,8 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; }