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| author | Boris BREZILLON <boris.brezillon@free-electrons.com> | 2014-06-06 14:36:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-06 16:08:08 -0700 |
| commit | 2fe121e1f5aa3bf31b418a9790db6c400e922291 (patch) | |
| tree | 0a0e52c511dbeb8d45b0e26a2399f5bcc7ed6737 /drivers/rtc/rtc-m48t59.c | |
| parent | 68164a73b1055191975419f5da7180294902f461 (diff) | |
| download | op-kernel-dev-2fe121e1f5aa3bf31b418a9790db6c400e922291.zip op-kernel-dev-2fe121e1f5aa3bf31b418a9790db6c400e922291.tar.gz | |
rtc: rtc-at91rm9200: fix infinite wait for ACKUPD irq
The rtc user must wait at least 1 sec between each time/calandar update
(see atmel's datasheet chapter "Updating Time/Calendar").
Use the 1Hz interrupt to update the at91_rtc_upd_rdy flag and wait for
the at91_rtc_wait_upd_rdy event if the rtc is not ready.
This patch fixes a deadlock in an uninterruptible wait when the RTC is
updated more than once every second. AFAICT the bug is here from the
beginning, but I think we should at least backport this fix to 3.10 and
the following longterm and stable releases.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Bryan Evenson <bevenson@melinkcorp.com>
Tested-by: Bryan Evenson <bevenson@melinkcorp.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-m48t59.c')
0 files changed, 0 insertions, 0 deletions
