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| author | Gabriele Mazzotta <gabriele.mzt@gmail.com> | 2016-09-20 01:12:43 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-09-21 22:08:42 +0200 |
| commit | 983bf1256edb477a376b6ce95adf36e13bc88f9a (patch) | |
| tree | 87339d47fde88ccc10a8a42c25c2c3875617c8d7 /drivers/rtc | |
| parent | 97ea1906b3c2201273ea6bb40c43c611c056ddb3 (diff) | |
| download | linux-983bf1256edb477a376b6ce95adf36e13bc88f9a.tar.gz | |
rtc: cmos: Clear ACPI-driven alarms upon resume
Currently ACPI-driven alarms are not cleared when they wake the system. As consequence, expired alarms must be manually cleared to program a new alarm. Fix this by correctly handling ACPI-driven alarms. More specifically, the ACPI specification [1] provides for two alternative implementations of the RTC. Depending on the implementation, the driver either clear the alarm from the resume callback or from ACPI interrupt handler: - The platform has the RTC wakeup status fixed in hardware (ACPI_FADT_FIXED_RTC is 0). In this case the driver can determine if the RTC was the reason of the wakeup from the resume callback by reading the RTC status register. - The platform has no fixed hardware feature event bits. In this case a GPE is used to wake the system and the driver clears the alarm from its handler. [1] http://www.acpi.info/DOWNLOADS/ACPI_5_Errata%20A.pdf Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-cmos.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index fddde655cbd4..e8f3a212d09a 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -899,6 +899,9 @@ static inline int cmos_poweroff(struct device *dev) #ifdef CONFIG_PM_SLEEP +static void cmos_check_acpi_rtc_status(struct device *dev, + unsigned char *rtc_control); + static int cmos_resume(struct device *dev) { struct cmos_rtc *cmos = dev_get_drvdata(dev); @@ -938,6 +941,9 @@ static int cmos_resume(struct device *dev) tmp &= ~RTC_AIE; hpet_mask_rtc_irq_bit(RTC_AIE); } while (mask & RTC_AIE); + + if (tmp & RTC_AIE) + cmos_check_acpi_rtc_status(dev, &tmp); } spin_unlock_irq(&rtc_lock); @@ -975,6 +981,20 @@ static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume); static u32 rtc_handler(void *context) { struct device *dev = context; + struct cmos_rtc *cmos = dev_get_drvdata(dev); + unsigned char rtc_control = 0; + unsigned char rtc_intr; + + spin_lock_irq(&rtc_lock); + if (cmos_rtc.suspend_ctrl) + rtc_control = CMOS_READ(RTC_CONTROL); + if (rtc_control & RTC_AIE) { + cmos_rtc.suspend_ctrl &= ~RTC_AIE; + CMOS_WRITE(rtc_control, RTC_CONTROL); + rtc_intr = CMOS_READ(RTC_INTR_FLAGS); + rtc_update_irq(cmos->rtc, 1, rtc_intr); + } + spin_unlock_irq(&rtc_lock); pm_wakeup_event(dev, 0); acpi_clear_event(ACPI_EVENT_RTC); @@ -1041,12 +1061,39 @@ static void cmos_wake_setup(struct device *dev) device_init_wakeup(dev, 1); } +static void cmos_check_acpi_rtc_status(struct device *dev, + unsigned char *rtc_control) +{ + struct cmos_rtc *cmos = dev_get_drvdata(dev); + acpi_event_status rtc_status; + acpi_status status; + + if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC) + return; + + status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status); + if (ACPI_FAILURE(status)) { + dev_err(dev, "Could not get RTC status\n"); + } else if (rtc_status & ACPI_EVENT_FLAG_SET) { + unsigned char mask; + *rtc_control &= ~RTC_AIE; + CMOS_WRITE(*rtc_control, RTC_CONTROL); + mask = CMOS_READ(RTC_INTR_FLAGS); + rtc_update_irq(cmos->rtc, 1, mask); + } +} + #else static void cmos_wake_setup(struct device *dev) { } +static void cmos_check_acpi_rtc_status(struct device *dev, + unsigned char *rtc_control) +{ +} + #endif #ifdef CONFIG_PNP |