From c214455f3205fa20819da6d67a8b20609ff786e7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 20 Jan 2012 12:24:47 +0100 Subject: [PATCH] ARM: 7297/1: smp_twd: make sure timer is stopped before registering it On secondary CPUs, the Timer Control Register is not reset to a sane value before the timer is registered, and the TRM doesn't seem to indicate any reset value either. In some cases, the kernel will take an interrupt too early, depending on what junk was present in the registers at reset time. The fix is to set the Timer Control Register to 0 before registering the clock_event_device and enabling the interrupt. Problem seen on VE (Cortex A5) and Tegra. Signed-off-by: Marc Zyngier Signed-off-by: Russell King --- arch/arm/kernel/smp_twd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index c8e938553d47..4285daa077b0 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -252,6 +252,8 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk) else twd_calibrate_rate(); + __raw_writel(0, twd_base + TWD_TIMER_CONTROL); + clk->name = "local_timer"; clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;