Re: [PATCH 2/7] watchdog: jz4740: Use devm_* functions

[Guenter Roeck]

On 12/28/2017 12:22 PM, Paul Cercueil wrote:
> Le jeu. 28 dÃc. 2017 Ã 21:19, Guenter Roeck <linux@xxxxxxxxxxxx> a Ãcrit :
> > On 12/28/2017 11:59 AM, Paul Cercueil wrote:
> > > Hi Guenter,
> > >
> > > Le jeu. 28 dÃc. 2017 Ã 18:48, Guenter Roeck <linux@xxxxxxxxxxxx> a Ãcrit :
> > > > On 12/28/2017 08:29 AM, Paul Cercueil wrote:
> > > > > - Use devm_clk_get instead of clk_get
> > > > > - Use devm_watchdog_register_device instead of watchdog_register_device
> > > > >
> > > > > Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> > > > > ---
> > > > > Â drivers/watchdog/jz4740_wdt.c | 27 ++++++++-------------------
> > > > > Â 1 file changed, 8 insertions(+), 19 deletions(-)
> > > > >
> > > > > diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
> > > > > index 6955deb100ef..92d6ca8ceb49 100644
> > > > > --- a/drivers/watchdog/jz4740_wdt.c
> > > > > +++ b/drivers/watchdog/jz4740_wdt.c
> > > > > @@ -178,40 +178,29 @@ static int jz4740_wdt_probe(struct platform_device *pdev)
> > > > > Â ÂÂÂÂÂ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > > > ÂÂÂÂÂ drvdata->base = devm_ioremap_resource(&pdev->dev, res);
> > > > > -ÂÂÂ if (IS_ERR(drvdata->base)) {
> > > > > -ÂÂÂÂÂÂÂ ret = PTR_ERR(drvdata->base);
> > > > > -ÂÂÂÂÂÂÂ goto err_out;
> > > > > -ÂÂÂ }
> > > > > +ÂÂÂ if (IS_ERR(drvdata->base))
> > > > > +ÂÂÂÂÂÂÂ return PTR_ERR(drvdata->base);
> > > > > Â -ÂÂÂ drvdata->rtc_clk = clk_get(&pdev->dev, "rtc");
> > > > > +ÂÂÂ drvdata->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
> > > > > ÂÂÂÂÂ if (IS_ERR(drvdata->rtc_clk)) {
> > > > > ÂÂÂÂÂÂÂÂÂ dev_err(&pdev->dev, "cannot find RTC clock\n");
> > > > > -ÂÂÂÂÂÂÂ ret = PTR_ERR(drvdata->rtc_clk);
> > > > > -ÂÂÂÂÂÂÂ goto err_out;
> > > > > +ÂÂÂÂÂÂÂ return PTR_ERR(drvdata->rtc_clk);
> > > > > ÂÂÂÂÂ }
> > > > > Â -ÂÂÂ ret = watchdog_register_device(&drvdata->wdt);
> > > > > +ÂÂÂ ret = devm_watchdog_register_device(&pdev->dev, &drvdata->wdt);
> > > > > ÂÂÂÂÂ if (ret < 0)
> > > > > -ÂÂÂÂÂÂÂ goto err_disable_clk;
> > > > > +ÂÂÂÂÂÂÂ return ret;
> > > > > Â ÂÂÂÂÂ platform_set_drvdata(pdev, drvdata);
> > > > > -ÂÂÂ return 0;
> > > > > Â -err_disable_clk:
> > > > > -ÂÂÂ clk_put(drvdata->rtc_clk);
> > > > > -err_out:
> > > > > -ÂÂÂ return ret;
> > > > > +ÂÂÂ return 0;
> > > > > Â }
> > > > > Â Â static int jz4740_wdt_remove(struct platform_device *pdev)
> > > > > Â {
> > > > > ÂÂÂÂÂ struct jz4740_wdt_drvdata *drvdata = platform_get_drvdata(pdev);
> > > > > Â -ÂÂÂ jz4740_wdt_stop(&drvdata->wdt);
> > > > > -ÂÂÂ watchdog_unregister_device(&drvdata->wdt);
> > > > > -ÂÂÂ clk_put(drvdata->rtc_clk);
> > > > > -
> > > > > -ÂÂÂ return 0;
> > > > > +ÂÂÂ return jz4740_wdt_stop(&drvdata->wdt);
> > > >
> > > > If the watchdog is running, the module can not be unloaded. Even if that wasn't
> > > > the case, this defeats both WDIOF_MAGICCLOSE and watchdog_set_nowayout().
> > > > Are you sure this is what you want ? If so, please call
> > > > watchdog_stop_on_unregister() before registration; this clarifies that this
> > > > is what you want, and you can drop the remove function.
> > > >
> > > > Thanks,
> > > > Guenter
> > >
> > > This patch does not change the behaviour. We always used that driver built-in; what
> > > should the behaviour be when unloading the module? Keep the watchdog hardware running
> > > if configured for 'nowayout'?
> >
> > One can still unload the driver. If you are fine with bypassing/dfeating nowayout
> > and WDIOF_MAGICCLOSE, may I ask why those are enabled in the first place ?
>
> Who knows? That code is very old :)

Probably copied from some other driver w/o thinking much about it.

> I'm fine with removing the remove() function completely, if you think it makes more sense.

Yes, I do, but I won't insist on it either.

Thanks,
Guenter