Hello, On 18/10/2018 16:52:30+0800, Baolin Wang wrote: > When registering one RTC device, it will check to see if there is an > alarm already set in RTC hardware by reading RTC alarm, at this time > we should always read the normal alarm put in always-on region by > checking the rtc->registered flag. > > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> > --- > drivers/rtc/rtc-sc27xx.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/rtc/rtc-sc27xx.c b/drivers/rtc/rtc-sc27xx.c > index 72bb002..b4eb3b3 100644 > --- a/drivers/rtc/rtc-sc27xx.c > +++ b/drivers/rtc/rtc-sc27xx.c > @@ -415,10 +415,14 @@ static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) > u32 val; > > /* > - * If aie_timer is enabled, we should get the normal alarm time. > + * Before RTC device is registered, it will check to see if there is an > + * alarm already set in RTC hardware, and we always read the normal > + * alarm at this time. > + * > + * Or if aie_timer is enabled, we should get the normal alarm time. > * Otherwise we should get auxiliary alarm time. > */ > - if (rtc->rtc && rtc->rtc->aie_timer.enabled == 0) > + if (rtc->rtc && rtc->rtc->registered && rtc->rtc->aie_timer.enabled == 0) Note that the driver should not access rtc->registered and rtc->aie_timer.enabled and this is a bit fragile. But, on the other hand, I currently don't have anything better to suggest. I was also planning to add an in-kernel API for multiple alarms but I'm not sure it will actually help in your case. Anyway, this is applied. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
