netdev - Re: [PATCH RFT 1/2] phylib: add device reset GPIO support

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Date:	Thu, 26 May 2016 21:00:00 +0200
From:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>
To:	Linus Walleij <linus.walleij@...aro.org>
Cc:	Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
	Grant Likely <grant.likely@...aro.org>,
	Rob Herring <robh+dt@...nel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	Florian Fainelli <f.fainelli@...il.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	Frank Rowand <frowand.list@...il.com>,
	Paweł Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	"ijc+devicetree@...lion.org.uk" <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH RFT 1/2] phylib: add device reset GPIO support

On Thu, May 26, 2016 at 11:00:55AM +0200, Linus Walleij wrote:
> On Thu, May 12, 2016 at 8:42 PM, Uwe Kleine-König
> <u.kleine-koenig@...gutronix.de> wrote:
> 
> > [added Linus Walleij to Cc, there is a question for you/him below]
> (...)
> >> +void mdio_device_reset(struct mdio_device *mdiodev, int value)
> >> +{
> >> +     if (mdiodev->reset)
> >> +             gpiod_set_value(mdiodev->reset, value);
> >
> > Before v4.6-rc1~108^2~91 it was not necessary to check for the first
> > parameter being non-NULL before calling gpiod_set_value. Linus, did you
> > change this on purpose?
> 
> Not really. And AFAICT it is still not necessary: what changed is that
> an error message will be printed by VALIDATE_DESC() if you do that.
> And that is proper I guess? I think it's sloppy code to randomly pass in
> NULL to a call and just expect it to bail out, it seems more like
> exercising the error path than something you'd normally rely on.
> 
> Or am I getting things wrong?

is the following sloppy?:

	somegpio = gpiod_get_optional(dev, "some", GPIOD_OUT_LOW);
	if (IS_ERR(somegpio))
		return PTR_ERR(somegpio);
	gpiod_set_value(somegpio, 1);

If not (as I assume) you really changed something as this might trigger
the warning.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |