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| author | Anthony Pighin (Nokia) <anthony.pighin@nokia.com> | 2025-11-25 20:35:19 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-02-21 00:49:17 +0300 |
| commit | 81be22cd4ace020045cc6d31255c6f7c071eb7c0 (patch) | |
| tree | 1d08f8a43b094c5ede7d2faa6d27cd53eb740126 | |
| parent | 8eeb611b3d16241559bbf81ae5d938368c87818c (diff) | |
| download | linux-81be22cd4ace020045cc6d31255c6f7c071eb7c0.tar.xz | |
rtc: interface: Alarm race handling should not discard preceding error
Commit 795cda8338ea ("rtc: interface: Fix long-standing race when setting
alarm") should not discard any errors from the preceding validations.
Prior to that commit, if the alarm feature was disabled, or the
set_alarm failed, a meaningful error code would be returned to the
caller for further action.
After, more often than not, the __rtc_read_time will cause a success
return code instead, misleading the caller.
An example of this is when timer_enqueue is called for a rtc-abx080x
device. Since that driver does not clear the alarm feature bit, but
instead relies on the set_alarm operation to return invalid, the discard
of the return code causes very different behaviour; i.e.
hwclock: select() to /dev/rtc0 to wait for clock tick timed out
Fixes: 795cda8338ea ("rtc: interface: Fix long-standing race when setting alarm")
Signed-off-by: Anthony Pighin (Nokia) <anthony.pighin@nokia.com>
Reviewed-by: Esben Haabendal <esben@geanix.com>
Tested-by: Nick Bowler <nbowler@draconx.ca>
Link: https://patch.msgid.link/BN0PR08MB6951415A751F236375A2945683D1A@BN0PR08MB6951.namprd08.prod.outlook.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/rtc/interface.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index b8b298efd9a9..1906f4884a83 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -457,7 +457,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) * are in, we can return -ETIME to signal that the timer has already * expired, which is true in both cases. */ - if ((scheduled - now) <= 1) { + if (!err && (scheduled - now) <= 1) { err = __rtc_read_time(rtc, &tm); if (err) return err; |