ARM: twd: register clockevents device before enabling PPI

The smp_twd clockevents driver currently enables the local timer PPI
before the clockevents device is registered. This can lead to a kernel
panic if a spurious timer interrupt is generated before registration
has completed since the kernel will treat it as an IPI timer.

This patch moves the clockevents device registration before the IRQ
unmasking so that we can always handle timer interrupts once they can
occur.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 2c277d40cee681ccc496239b3ab6724259a35756..01c186222f3b9d132c670bdba6721a7b3b8f50ce 100644 (file)
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -137,8 +137,8 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
        clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk);
        clk->min_delta_ns = clockevent_delta2ns(0xf, clk);
 
+       clockevents_register_device(clk);
+
        /* Make sure our local interrupt controller has this enabled */
        gic_enable_ppi(clk->irq);
-
-       clockevents_register_device(clk);
 }