[PATCH] rtc: rtc-at91rm9200: fix lost ACKUPD interrupt
From: Bryan Evenson <hidden>
Date: 2014-05-05 21:00:41
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Boris,
-----Original Message----- From: Boris BREZILLON [mailto:boris.brezillon at 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 at lists.infradead.org; Alessandro Zummo; rtc- linux at googlegroups.com; linux-kernel at 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 <redacted> Reported-by: Bryan Evenson <redacted> --- 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
quoted hunk ↗ jump to hunk
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 index3281c90..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, structrtc_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