[PATCH 109/118] drivers/rtc/rtc-cmos.c: don't disable hpet emulation on suspend

[Luis Henriques]

3.5.7.12 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Derek Basehore <dbasehore at chromium.org>

commit e005715efaf674660ae59af83b13822567e3a758 upstream.

There's a bug where rtc alarms are ignored after the rtc cmos suspends
but before the system finishes suspend.  Since hpet emulation is
disabled and it still handles the interrupts, a wake event is never
registered which is done from the rtc layer.

This patch reverts commit d1b2efa83fbf ("rtc: disable hpet emulation on
suspend") which disabled hpet emulation.  To fix the problem mentioned
in that commit, hpet_rtc_timer_init() is called directly on resume.

Signed-off-by: Derek Basehore <dbasehore at chromium.org>
Cc: Maxim Levitsky <maximlevitsky at gmail.com>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Ingo Molnar <mingo at elte.hu>
Cc: "Rafael J. Wysocki" <rjw at sisk.pl>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/rtc/rtc-cmos.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 4267789..6a4adf7 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -805,9 +805,8 @@ static int cmos_suspend(struct device *dev)
 			mask = RTC_IRQMASK;
 		tmp &= ~mask;
 		CMOS_WRITE(tmp, RTC_CONTROL);
+		hpet_mask_rtc_irq_bit(mask);
 
-		/* shut down hpet emulation - we don't need it for alarm */
-		hpet_mask_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
 		cmos_checkintr(cmos, tmp);
 	}
 	spin_unlock_irq(&rtc_lock);
@@ -872,6 +871,7 @@ static int cmos_resume(struct device *dev)
 			rtc_update_irq(cmos->rtc, 1, mask);
 			tmp &= ~RTC_AIE;
 			hpet_mask_rtc_irq_bit(RTC_AIE);
+			hpet_rtc_timer_init();
 		} while (mask & RTC_AIE);
 		spin_unlock_irq(&rtc_lock);
 	}
-- 
1.8.1.2