[PATCH] watchdog: imxwd: suspend watchdog timer in low power mode

Sascha Hauer sha at pengutronix.de
Mon Jan 3 01:05:45 PST 2022

On Thu, Dec 16, 2021 at 01:26:53PM +0100, Andrej Picej wrote:
> Watchdog timer should be disabled in low power mode. The problem that
> was observed was that when the watchdog is started from barebox, kernel
> driver doesn't do its own setup again and in turn this bit is left
> unset. Moreover, this bit is write-once and has to be set before
> enabling the watchdog, leaving responsibility for proper setup to a
> party first using the watchdog timer (e.g. bootloader). Issue manifests
> itself later on, when device enters low power mode (e.g. suspend) for
> more amount of time than what is maximum watchdog timeout (128s). After
> that period of time, device will not recover ever as there is no service
> patting the watchdog (CPU is suspended). This means that the device can
> hang in suspend mode or it performs an unexpected reset.
> Thus to avoid suspend/resume problems when watchdog is started already
> in the bootloader, align bootloader driver settings with kernel settings.
> Kernel driver has been already setting this bit since 2014.
> Signed-off-by: Andrej Picej <andrej.picej at norik.com>
> ---
>  drivers/watchdog/imxwd.c | 4 ++++
>  1 file changed, 4 insertions(+)

Applied, thanks


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