drivers/rtc/rtc-cmos.c: don't disable hpet emulation on suspend

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@chromium.org>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index af97c94e8a3a..cc5bea9c4b1c 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -804,9 +804,8 @@ 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);
@@ -870,6 +869,7 @@ 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);
         }