Commits
Gabriele Mazzotta committed 983bf1256ed
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>