From: john stultz Date: Thu, 5 May 2011 01:16:50 +0000 (-0700) Subject: clocksource: Install completely before selecting X-Git-Tag: v2.6.38.7~15 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f8c47371b566131cf60263ce8fe7a593da151387;p=karo-tx-linux.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 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 6519cf62d9cd..0e17c10f8a9d 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -685,8 +685,8 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) /* Add clocksource to the clcoksource list */ mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; } @@ -706,8 +706,8 @@ int clocksource_register(struct clocksource *cs) mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; }