diff options
| author | Boris BREZILLON <boris.brezillon@free-electrons.com> | 2014-06-06 14:36:09 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-26 15:15:37 -0400 |
| commit | 5802b6a0e257b54656bf1f776b3ff48e006c7239 (patch) | |
| tree | 3813267b7e6e0bdcda44e9abf3551667e86a56d7 /kernel/sysctl_binary.c | |
| parent | 0c5b3b80f7aeba9b8d25e12f7b321d148a1b1cb9 (diff) | |
rtc: rtc-at91rm9200: fix infinite wait for ACKUPD irq
commit 2fe121e1f5aa3bf31b418a9790db6c400e922291 upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/sysctl_binary.c')
0 files changed, 0 insertions, 0 deletions