Re: [PATCH] rtc: omap: wait for !BUSY before reading time for the power-off alarm

[sashiko-bot@kernel.org]

> omap_rtc_power_off_program() reads the time registers to arm ALARM2
> one second ahead, but does not wait for STATUS.BUSY to clear first,
> unlike omap_rtc_read_time(). The time registers must not be accessed
> while BUSY is set, as the counters may be partway through an update.
> 
> A read during an update can return, for example, seconds already
> wrapped to 0 with minutes still at the old value. The rollover check
> after arming only compares the seconds register, which no longer
> changes, so it passes and ALARM2 is armed for a time that has already
> passed. Power-off or rtc-only suspend then waits for an alarm that
> does not fire as intended.
> 
> Call rtc_wait_not_busy() before the read, as omap_rtc_read_time()
> does. Both callers run with local interrupts disabled, as the access
> window requires.
> 
> Fixes: 222a12fca604 ("rtc: omap: add support for pmic_power_en")
> Assisted-by: LLM
> Signed-off-by: Rosen Penev <rosenp@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261004215914.397512-1-rosenp@gmail.com?part=1