From: Stephen Boyd Date: Fri, 15 Mar 2013 03:31:37 +0000 (-0700) Subject: ARM: msm: Stop counting before reprogramming clockevent X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=4080d2d11a2d572228c2b8d02406e997b87ba6a5;p=deliverable%2Flinux.git ARM: msm: Stop counting before reprogramming clockevent If the clockevent is forcibly reprogrammed to have a different match value we mistakenly assume the timer is not ticking and program a new match value while the timer is running. Although we clear the timer before programming a new match, it's better to stop the timer before clearing it so that we're sure the proper amount of ticks are counted. Failure to do so can lead to missed ticks and system hangs. Signed-off-by: Stephen Boyd Signed-off-by: David Brown --- diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c index 2969027f02fa..f9fd77e8f1f5 100644 --- a/arch/arm/mach-msm/timer.c +++ b/arch/arm/mach-msm/timer.c @@ -62,7 +62,10 @@ static int msm_timer_set_next_event(unsigned long cycles, { u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE); - writel_relaxed(0, event_base + TIMER_CLEAR); + ctrl &= ~TIMER_ENABLE_EN; + writel_relaxed(ctrl, event_base + TIMER_ENABLE); + + writel_relaxed(ctrl, event_base + TIMER_CLEAR); writel_relaxed(cycles, event_base + TIMER_MATCH_VAL); writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE); return 0;