Messages in this thread | | | Date | Tue, 20 Sep 2016 00:21:01 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH v3 1/2] rtc-cmos: Clear ACPI-driven alarms upon resume |
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Hi Gabriele,
Thanks for your persistence! Both patches look good. Can you fix the build issues reported by kbuild?
On 14/09/2016 at 21:08:40 +0200, Gabriele Mazzotta wrote : > 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> > --- > 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 >
-- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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