[ARM] Fix timer damage from d3d74453c34f8fd87674a8cf5b8a327c68f22e99

Move the xtime write mode seqlock into timer_tick(), so it only
surrounds the call to do_timer().

This avoids a deadlock in update_process_times() ...
hrtimer_get_softirq_time() which tries to get a read mode seqlock
on xtime, thereby preventing booting.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index e59b5b84168d..b5867eca1d0b 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -325,7 +325,9 @@ void timer_tick(void)
         profile_tick(CPU_PROFILING);
         do_leds();
         do_set_rtc();
+        write_seqlock(&xtime_lock);
         do_timer(1);
+        write_sequnlock(&xtime_lock);
 #ifndef CONFIG_SMP
         update_process_times(user_mode(get_irq_regs()));
 #endif