Re: [PATCH v2 3/3] watchdog: pretimeout: record PSC reason on watchdog pretimeout

[Guenter Roeck <linux@roeck-us.net>]

On 7/22/26 08:13, Faruque Ansari wrote:
> Update the PSC reset reason by invoking set_psc_reason(PSCR_WATCHDOG_PRETIMEOUT)
> from watchdog_notify_pretimeout() before either the panic or noop governor
> runs, so the reset cause is committed to persistent storage before the
> system goes down.
> 
> Signed-off-by: Faruque Ansari <faruque.ansari@oss.qualcomm.com>
> ---
>   drivers/watchdog/watchdog_pretimeout.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
> index 02e09b9e396d..ea48d4eca4aa 100644
> --- a/drivers/watchdog/watchdog_pretimeout.c
> +++ b/drivers/watchdog/watchdog_pretimeout.c
> @@ -4,6 +4,7 @@
>    */
>   
>   #include <linux/list.h>
> +#include <linux/reboot.h>
>   #include <linux/slab.h>
>   #include <linux/spinlock.h>
>   #include <linux/string.h>
> @@ -103,6 +104,8 @@ void watchdog_notify_pretimeout(struct watchdog_device *wdd)
>   {
>   	unsigned long flags;
>   
> +	set_psc_reason(PSCR_WATCHDOG_PRETIMEOUT);
> +

A call to watchdog_notify_pretimeout() does not necessarily reset the system.
It only resets the system if the panic governor is active. Given that,
I think this is a bit misleading. If the "noop" governor is active and the
system crashes later due to a completely unrelated panic, the restart reason
will be wrongly logged as pretimeout.

Guenter
>   	spin_lock_irqsave(&pretimeout_lock, flags);
>   	if (!wdd->gov) {
>   		spin_unlock_irqrestore(&pretimeout_lock, flags);
>