linux-kernel - [PATCH] rtc: allow rtc_read_alarm without read

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Date:   Tue, 14 Feb 2023 23:27:53 +0100
From:   alexandre.belloni@...tlin.com
To:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     Zhipeng Wang <zhipeng.wang_1@....com>,
        Marcel Ziswiler <marcel.ziswiler@...adex.com>,
        linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] rtc: allow rtc_read_alarm without read_alarm callback

From: Alexandre Belloni <alexandre.belloni@...tlin.com>

.read_alarm is not necessary to read the current alarm because it is
recorded in the aie_timer and so rtc_read_alarm() will never call
rtc_read_alarm_internal() which is the only function calling the callback.

Reported-by: Zhipeng Wang <zhipeng.wang_1@....com>
Reported-by: Marcel Ziswiler <marcel.ziswiler@...adex.com>
Fixes: 7ae41220ef58 ("rtc: introduce features bitfield")
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
---
 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 7c30cb3c764d..499d89150afc 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -392,7 +392,7 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 		return err;
 	if (!rtc->ops) {
 		err = -ENODEV;
-	} else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->read_alarm) {
+	} else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) {
 		err = -EINVAL;
 	} else {
 		memset(alarm, 0, sizeof(struct rtc_wkalrm));
-- 
2.39.1