Re: [PATCH v2 4/8] watchdog: msc313e_wdt: Convert to DEFINE_SIMPLE_DEV_PM_OPS()

[Tzung-Bi Shih <tzungbi@kernel.org>]

On Mon, Sep 14, 2026 at 09:20:11AM +0000, sashiko-bot@kernel.org wrote:
> > diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c
> > index 4a5cce2a16b18..a77ff57a44571 100644
> > --- a/drivers/watchdog/msc313e_wdt.c
> > +++ b/drivers/watchdog/msc313e_wdt.c
> 
> [ ... ]
> 
> > -static int __maybe_unused msc313e_wdt_resume(struct device *dev)
> > +static int msc313e_wdt_resume(struct device *dev)
> >  {
> >  	struct msc313e_wdt_priv *priv = dev_get_drvdata(dev);
> >  
> >  	if (watchdog_active(&priv->wdev) || watchdog_hw_running(&priv->wdev))
> >  		msc313e_wdt_start(&priv->wdev);
> >  
> >  	return 0;
> 
> [Severity: High]
> This is a pre-existing issue, but does msc313e_wdt_resume() need to handle
> the return value of msc313e_wdt_start()?
> 
> If clk_prepare_enable() fails inside msc313e_wdt_start():
> 
> msc313e_wdt_start() {
> 	...
> 	err = clk_prepare_enable(priv->clk);
> 	if (err)
> 		return err;
> 	...
> }
> 
> The error is returned to msc313e_wdt_resume(), which discards it and returns
> 0. Because the watchdog core state still considers the hardware active,
> could subsequent operations like watchdog ping perform writes to unclocked
> hardware registers (such as REG_WDT_CLR) and trigger a bus fault or system
> crash?

https://lore.kernel.org/all/20260912163334.28636-1-tzungbi@kernel.org tries
to address the issue.