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 <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>

diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 2969027f02fa57045ec7bb3d65d7a98927cfde3c..f9fd77e8f1f5a998af7b8f15e12af3afd5bcc299 100644 (file)
--- 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;