Commit 0fedce72 authored by Anthony Pighin (Nokia)'s avatar Anthony Pighin (Nokia) Committed by Alexandre Belloni
Browse files

rtc: abx80x: Disable alarm feature if no interrupt attached 



Commit 795cda83 ("rtc: interface: Fix long-standing race when setting
alarm") exposed an issue where the rtc-abx80x driver does not clear the
alarm feature bit, but instead relies on the set_alarm operation to return
invalid.

For example, when a RTC_UIE_ON ioctl is handled, it should abort at the
feature validation. Instead, it proceeds to the rtc_timer_enqueue(),
which used to return an error from the set_alarm call. However,
following the race condition handling, which likely should not be
discarding predecing errors, a success condition is returned to the
ioctl() caller. This results in (for example):
    hwclock: select() to /dev/rtc0 to wait for clock tick timed out

Notwithstanding the validity of the race condition handling, if an interrupt
wasn't specified, or could not be attached, the driver should clear the
alarm feature bit.

Fixes: 718a820a ("rtc: abx80x: add alarm support")
Signed-off-by: default avatarAnthony Pighin <anthony.pighin@nokia.com>
Link: https://patch.msgid.link/BN0PR08MB69510928028C933749F4139383D1A@BN0PR08MB6951.namprd08.prod.outlook.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 30c4d2f2

drivers/rtc/rtc-abx80x.c

+2 −0
Original line number Diff line number Diff line
@@ -932,6 +932,8 @@ static int abx80x_probe(struct i2c_client *client) 
			client->irq = 0;

		}

	}

	if (client->irq <= 0)

		clear_bit(RTC_FEATURE_ALARM, priv->rtc->features);



	err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);

	if (err) {