On 05/10/2020 09:13:08-0400, Peter Geis wrote: > Good Morning, > > While testing suspend to ram on the Ouya, I encountered an interesting > issue with the rtc-tps65910 driver. > Attempting to use rtc-wake on the default configuration returned: > rtcwake: /dev/rtc0 not enabled for wakeup events > This is due to: > eb5eba4ef722 drivers/rtc/rtc-tps65910.c: enable/disable wake in suspend/resume > This commit changed this driver's behavior to not enable wakeup by > default, but enables it when entering sleep mode. > This seems to be odd behavior to me. > Looking at a few other rtc drivers show they simply enable themselves > as wakeup sources by default. > > I also found the sysfs entries are at /sys/devices/ .. > /tps65910-rtc/power but are missing at /sys/class/rtc/rtc0/power/ > > I have two questions. > - Should the sysfs wakeup entries be missing at /sys/class/rtc/rtc0/power/ ? I would be in /sys/class/rtc/rtc0/device/power > - Shouldn't a rtc be enabled as a wakeup source by default? > The short answer is no, the reason being that not all RTCs are connected to an IRQ or a pin that can wakeup or start the platform. What should be done is enabling wakeup only when interrupts are available or the wakeup-source property is in the rtc device tree node. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
