Re: [PATCH 1/2] i2c-s3c2410: Rework device type handling

From: Wolfram Sang
Date: Tue Apr 24 2012 - 10:44:19 EST


On Tue, Apr 24, 2012 at 10:40:49AM +0200, Karol Lewandowski wrote:
> On 23.04.2012 20:20, Wolfram Sang wrote:
>
> Hi!
>
> >> -static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
> >> +static inline unsigned int s3c24xx_get_device_quirks(struct platform_device *pdev)
> >> {
> >> - struct platform_device *pdev = to_platform_device(i2c->dev);
> >> - enum s3c24xx_i2c_type type;
> >> -
> >> -#ifdef CONFIG_OF
> >> - if (i2c->dev->of_node)
> >> - return of_device_is_compatible(i2c->dev->of_node,
> >> - "samsung,s3c2440-i2c");
> >> -#endif
> >> + if (pdev->dev.of_node) {
> >> + const struct of_device_id *match;
> >> + match = of_match_node(&s3c24xx_i2c_match, pdev->dev.of_node);
> >
> > I'd appreciate a comment explaining why match can't be NULL here (as to
> > my understanding, it can't). Or just check for it, but this way it looks
> > a bit fishy and people (hopefully ;)) will ask about it.
>
>
> My understanding is that it can't be null for exactly same reason why
> platform_get_device_id(pdev) can't be null either (see below).
>
> I.e. prerequisite for this code to be run at all (as it's called from
> driver's .probe()) is to be already matched against very same match
> table.

Yes, I agree. Yet, this is not obvious and people might try to fix it
(especially since programs like smatch report it as potentially
dangerous). Ah, whatever, I could simply apply the fix then :) OK.

Regards,

Wolfram

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |

Attachment: signature.asc
Description: Digital signature