From 998a06051afe6cba392eab66fa0ef1d7e7376f6c Mon Sep 17 00:00:00 2001 From: Derek Basehore Date: Wed, 3 Jul 2013 15:07:54 -0700 Subject: [PATCH] drivers/rtc/rtc-cmos.c: work around bios clearing rtc control The bios may clear the rtc control register when resuming the system. Since the cmos interrupt handler may now be run before the rtc_cmos is resumed, this can cause the interrupt handler to ignore an alarm since the alarm bit is not set in the rtc control register. To work around this, check if the rtc_cmos is suspended and use the stored value for the rtc control register. Signed-off-by: Derek Basehore Reviewed-by: Sameer Nanda Cc: Alessandro Zummo Cc: Jingoo Han Cc: Steven Rostedt Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-cmos.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index a6727d977330..be06d7150de5 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -556,17 +556,24 @@ static irqreturn_t cmos_interrupt(int irq, void *p) rtc_control = CMOS_READ(RTC_CONTROL); if (is_hpet_enabled()) irqstat = (unsigned long)irq & 0xF0; - irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF; + + /* If we were suspended, RTC_CONTROL may not be accurate since the + * bios may have cleared it. + */ + if (!cmos_rtc.suspend_ctrl) + irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF; + else + irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF; /* All Linux RTC alarms should be treated as if they were oneshot. * Similar code may be needed in system wakeup paths, in case the * alarm woke the system. */ if (irqstat & RTC_AIE) { + cmos_rtc.suspend_ctrl &= ~RTC_AIE; rtc_control &= ~RTC_AIE; CMOS_WRITE(rtc_control, RTC_CONTROL); hpet_mask_rtc_irq_bit(RTC_AIE); - CMOS_READ(RTC_INTR_FLAGS); } spin_unlock(&rtc_lock); @@ -839,21 +846,23 @@ static inline int cmos_poweroff(struct device *dev) static int cmos_resume(struct device *dev) { struct cmos_rtc *cmos = dev_get_drvdata(dev); - unsigned char tmp = cmos->suspend_ctrl; + unsigned char tmp; + if (cmos->enabled_wake) { + if (cmos->wake_off) + cmos->wake_off(dev); + else + disable_irq_wake(cmos->irq); + cmos->enabled_wake = 0; + } + + spin_lock_irq(&rtc_lock); + tmp = cmos->suspend_ctrl; + cmos->suspend_ctrl = 0; /* re-enable any irqs previously active */ if (tmp & RTC_IRQMASK) { unsigned char mask; - if (cmos->enabled_wake) { - if (cmos->wake_off) - cmos->wake_off(dev); - else - disable_irq_wake(cmos->irq); - cmos->enabled_wake = 0; - } - - spin_lock_irq(&rtc_lock); if (device_may_wakeup(dev)) hpet_rtc_timer_init(); @@ -873,8 +882,8 @@ static int cmos_resume(struct device *dev) tmp &= ~RTC_AIE; hpet_mask_rtc_irq_bit(RTC_AIE); } while (mask & RTC_AIE); - spin_unlock_irq(&rtc_lock); } + spin_unlock_irq(&rtc_lock); dev_dbg(dev, "resume, ctrl %02x\n", tmp);