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Date: Fri, 20 Jan 2012 09:39:16 -0800
From: Tony Lindgren <tony@atomide.com>
To: Stephen Warren <swarren@nvidia.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linus Walleij <linus.walleij@stericsson.com>,
        Barry Song <21cnbao@gmail.com>,
        Haojian Zhuang <haojian.zhuang@marvell.com>,
        Grant Likely <grant.likely@secretlab.ca>,
        Thomas Abraham <thomas.abraham@linaro.org>,
        Rajendra Nayak <rajendra.nayak@linaro.org>,
        Dong Aisheng <dong.aisheng@linaro.org>,
        Shawn Guo <shawn.guo@freescale.com>
Subject: Re: [PATCH 2/4] pinctrl: Fix pinmux_hog_maps when ctrl_dev_name is
 not set
Message-ID: <20120120173915.GP22818@atomide.com>
References: <20120120161610.21955.25082.stgit@kaulin.local>
 <20120120161727.21955.7437.stgit@kaulin.local>
 <74CDBE0F657A3D45AFBB94109FB122FF1780DAB383@HQMAIL01.nvidia.com>
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* Stephen Warren <swarren@nvidia.com> [120120 08:24]:
> Tony Lindgren wrote at Friday, January 20, 2012 9:17 AM:
> > The ctrl_dev_name is optional for struct pinmux_map assuming
> > that ctrl_dev is set. Without this patch we can get:
> > 
> > Unable to handle kernel NULL pointer dereference at virtual address 00000000
> 
> > diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
> 
> 
> > @@ -992,9 +992,12 @@ int pinmux_hog_maps(struct pinctrl_dev *pctldev)
> > 
> >  	for (i = 0; i < pinmux_maps_num; i++) {
> >  		struct pinmux_map const *map = &pinmux_maps[i];
> > +		int match_found = 0;
> > 
> > -		if (((map->ctrl_dev == dev) ||
> > -		     !strcmp(map->ctrl_dev_name, devname)) &&
> > +		if (map->ctrl_dev_name && !strcmp(map->ctrl_dev_name, devname))
> > +				match_found = 1;
> > +
> > +		if (((map->ctrl_dev == dev) || match_found) &&
> >  		    map->hog_on_boot) {
> >  			/* OK time to hog! */
> >  			ret = pinmux_hog_map(pctldev, map);
> 
> Wouldn't it be better if match_found was true for all matching cases,
> in other words for the new code to be:
> 
> 		int match_found = 0;
> 
> 		if (map->ctrl_dev_name && !strcmp(map->ctrl_dev_name, devname))
> 				match_found = 1;
> 		if (map->ctrl_dev == dev)
> 				match_found = 1;
> 		if (match_found && map->hog_on_boot) {

OK will take a look, that would make the code easier to read.

Regards,

Tony