Re: [PATCH] rtc: cros-ec: Limit RTC alarm range if needed

[Brian Norris]

On Fri, Oct 28, 2022 at 05:54:00PM -0700, Guenter Roeck wrote:
> RTC chips on some older Chromebooks can only handle alarms less than 24
> hours in the future. Attempts to set an alarm beyond that range fails.
> The most severe impact of this limitation is that suspend requests fail
> if alarmtimer_suspend() tries to set an alarm for more than 24 hours
> in the future.
> 
> Try to set the real-time alarm to just below 24 hours if setting it to
> a larger value fails to work around the problem. While not perfect, it
> is better than just failing the call. A similar workaround is already
> implemented in the rtc-tps6586x driver.
> 
> Drop error messages in cros_ec_rtc_get() and cros_ec_rtc_set() since the
> calling code also logs an error and to avoid spurious error messages if
> setting the alarm ultimately succeeds.
> 
> Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Tested-by: Brian Norris <briannorris@xxxxxxxxxxxx>