Messages in this thread | | | From | Bryan Evenson <> | Subject | RE: [PATCH] rtc: rtc-at91rm9200: fix lost ACKUPD interrupt | Date | Mon, 5 May 2014 20:44:48 +0000 |
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Boris,
> -----Original Message----- > From: Boris BREZILLON [mailto:boris.brezillon@free-electrons.com] > Sent: Monday, May 05, 2014 4:23 PM > To: Bryan Evenson > Cc: Andrew Victor; Nicolas Ferre; Jean-Christophe Plagniol-Villard; linux-arm- > kernel@lists.infradead.org; Alessandro Zummo; rtc- > linux@googlegroups.com; linux-kernel@vger.kernel.org; Boris BREZILLON > Subject: [PATCH] rtc: rtc-at91rm9200: fix lost ACKUPD interrupt > > If an alarm interrupt raises just after the CR register is written and before the > ACKUPD is unmasked the ACKUPD bit might be cleaned up without waking > up the waiting thread. > > Unmask the ACKUPD interrupt before writing the CR register so that the > ACKUPD cannot be lost. > > Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com> > Reported-by: Bryan Evenson <bevenson@melinkcorp.com> > --- > Hello Bryan, > > Could you try to apply this patch and tell me if it fixes your bug ? >
I'll incorporate the patch and see what happens. I'll be able to let you know the results tomorrow morning.
Regards, Bryan
> Best Regards, > > Boris > > drivers/rtc/rtc-at91rm9200.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index > 3281c90..c16c423 100644 > --- a/drivers/rtc/rtc-at91rm9200.c > +++ b/drivers/rtc/rtc-at91rm9200.c > @@ -163,9 +163,9 @@ static int at91_rtc_settime(struct device *dev, struct > rtc_time *tm) > > /* Stop Time/Calendar from counting */ > cr = at91_rtc_read(AT91_RTC_CR); > + at91_rtc_write_ier(AT91_RTC_ACKUPD); > at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | > AT91_RTC_UPDTIM); > > - at91_rtc_write_ier(AT91_RTC_ACKUPD); > wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD > interrupt */ > at91_rtc_write_idr(AT91_RTC_ACKUPD); > > -- > 1.8.3.2
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