[PATCH] watchdog: prevent the STPMIC1 watchdog probe from modifying the global turn-OFF behaviour

[Ahmad Fatoum]

Hello

On 11.02.21 16:03, Leonard Göhrs wrote:
> According to Table 12 in the STPMIC1-datasheet (Rev 7 - December 2020)
> there are the following turn-OFF conditions:
> 
> - Software switch-OFF*
> - PONKEYn long key press*
> - Thermal shutdown
> - Overcurrent protection
> - Watchdog*
> - VIN_OK_Fall*
> 
> The conditions marked with an * can be re-configured from turn-Off conditions
> to restart requests using the RREQ_EN-bit in the CR register
> (Called RESTART_REQUEST_ENABLED in Linux/Barebox).
> 
> The watchdog code enabled this bit in it's probe function to trigger a restart
> on a watchdog event. This may however result in unexpected behaviour,
> like a long-press of the PONKEY resulting in a restart instead of a turn-off
> when the watchdog is enabled vs. when it is not.
> 
> This change does not affect the restart and poweroff functionality provided by
> the wdt driver, as the restart-/poweroff-handlers explicitly set/clear the
> RESTART_REQUEST_ENABLED flag when triggering a software turn-OFF.
> 
> To prevent unexpected behaviour of the PONKEYn and other turn-OFF sources the
> RESTART_REQUEST_ENABLED configuration in the probe function can and should thus be removed.
> 
> Signed-off-by: Leonard Göhrs <l.goehrs at pengutronix.de>

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

> ---
>  drivers/watchdog/stpmic1_wdt.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c
> index 12280f144..105ba39fb 100644
> --- a/drivers/watchdog/stpmic1_wdt.c
> +++ b/drivers/watchdog/stpmic1_wdt.c
> @@ -174,10 +174,6 @@ static int stpmic1_wdt_probe(struct device_d *dev)
>  	wdd->set_timeout = stpmic1_wdt_set_timeout;
>  	wdd->timeout_max = PMIC_WDT_MAX_TIMEOUT;
>  
> -	/* have the watchdog reset, not power-off the system */
> -	regmap_write_bits(wdt->regmap, SWOFF_PWRCTRL_CR,
> -			  RESTART_REQUEST_ENABLED, RESTART_REQUEST_ENABLED);
> -
>  	ret = watchdog_register(wdd);
>  	if (ret) {
>  		dev_err(dev, "Failed to register watchdog device\n");
> 

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