[PATCH 3/5] omap: DMTIMER: Ack pending interrupt always when stopping a timer

Tony Lindgren tony at atomide.com
Tue Jun 8 08:03:31 EDT 2010


From: Tero Kristo <tero.kristo at nokia.com>

The kernel timer queue is being run currently from a GP timer running in a one
shot mode, which works in a way that when it expires, it will also stop.
Usually during this situation, the interrupt handler will ack the interrupt,
load a new value to the timer and start it again. During suspend, the
situation is slightly different, as we disable interrupts just before
timekeeping is suspended, which leaves a small window where the timer can
expire before it is stopped, and will leave the interrupt flag pending.
This pending interrupt will prevent ARM sleep entry, thus now we ack it always
when we are attempting to stop a timer.

Signed-off-by: Tero Kristo <tero.kristo at nokia.com>
Acked-by: Kevin Hilman <khilman at deeprootsystems.com>
[tony at atomide.com: removed the ifdef to make the patch cover omap1 also]
Signed-off-by: Tony Lindgren <tony at atomide.com>
---
 arch/arm/plat-omap/dmtimer.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
index c64875f..44bafda 100644
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c
@@ -541,11 +541,11 @@ void omap_dm_timer_stop(struct omap_dm_timer *timer)
 		  * timer is stopped
 		  */
 		udelay(3500000 / clk_get_rate(timer->fclk) + 1);
-		/* Ack possibly pending interrupt */
-		omap_dm_timer_write_reg(timer, OMAP_TIMER_STAT_REG,
-				OMAP_TIMER_INT_OVERFLOW);
 #endif
 	}
+	/* Ack possibly pending interrupt */
+	omap_dm_timer_write_reg(timer, OMAP_TIMER_STAT_REG,
+			OMAP_TIMER_INT_OVERFLOW);
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_stop);
 




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