From 81be22cd4ace020045cc6d31255c6f7c071eb7c0 Mon Sep 17 00:00:00 2001 From: "Anthony Pighin (Nokia)" Date: Tue, 25 Nov 2025 17:35:19 +0000 Subject: [PATCH] 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) Reviewed-by: Esben Haabendal Tested-by: Nick Bowler Link: https://patch.msgid.link/BN0PR08MB6951415A751F236375A2945683D1A@BN0PR08MB6951.namprd08.prod.outlook.com Signed-off-by: Alexandre Belloni --- drivers/rtc/interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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; -- 2.47.3