[rtc-linux] [PATCH v3 1/2] rtc-cmos: Clear ACPI-driven alarms upon resume
From: Gabriele Mazzotta <hidden>
Date: 2016-09-14 19:09:57
Also in:
lkml
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
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 <redacted> --- drivers/rtc/rtc-cmos.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 1dec52f..6042257 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c@@ -939,6 +939,22 @@ 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) && + !(acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)) { + acpi_status status; + acpi_event_status rtc_status; + + 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) { + tmp &= ~RTC_AIE; + CMOS_WRITE(tmp, RTC_CONTROL); + rtc_update_irq(cmos->rtc, 1, mask); + } + } } spin_unlock_irq(&rtc_lock);
@@ -976,6 +992,22 @@ 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; + unsigned char rtc_intr; + + spin_lock_irq(&rtc_lock); + if (!cmos_rtc.suspend_ctrl) + rtc_control = cmos_rtc.suspend_ctrl; + else + 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);
--
2.9.3
--
You received this message because you are subscribed to "rtc-linux".
Membership options at http://groups.google.com/group/rtc-linux .
Please read http://groups.google.com/group/rtc-linux/web/checklist
before submitting a driver.
---
You received this message because you are subscribed to the Google Groups "rtc-linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.