Re: [PATCH] i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls

From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Doug Anderson <dianders@chromium.org>
Cc: "Wolfram Sang" <wsa@the-dreams.de>,
	"Tony Lindgren" <tony@atomide.com>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Thierry Reding" <thierry.reding@avionic-design.de>,
	"Sekhar Nori" <nsekhar@ti.com>,
	linux-i2c@vger.kernel.org, "Guan Xuetao" <gxt@mprc.pku.edu.cn>,
	"Kevin Hilman" <khilman@ti.com>,
	"Sonic Zhang" <sonic.zhang@analog.com>,
	linux-arm-kernel@lists.infradead.org,
	"Deepak Sikri" <deepak.sikri@st.com>,
	"Havard Skinnemoen" <hskinnemoen@gmail.com>,
	"Marek Vasut" <marex@denx.de>, "Pawel Moll" <pawel.moll@arm.com>,
	"Stephen Warren" <swarren@wwwdotorg.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Rob Herring" <rob.herring@calxeda.com>,
	uclinux-dist-devel@blackfin.uclinux.org,
	"Jean Delvare" <khali@linux-fr.org>,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Ben Dooks (embedded platforms)" <ben-linux@fluff.org>,
	"Barry Song" <baohua.song@csr.com>,
	linux-omap@vger.kernel.org, "Oskar Schirmer" <oskar@scara.com>,
	"Fabio Estevam" <fabio.estevam@freescale.com>,
	davinci-linux-open-source@linux.davincidsp.com,
	"Shawn Guo" <shawn.guo@linaro.org>,
	"Jim Cromie" <jim.cromie@gmail.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Tomoya MORINAGA" <tomoya.rohm@gmail.com>,
	linux-kernel@vger.kernel.org,
	"Kyungmin Park" <kyungmin.park@samsung.com>,
	"Viresh Kumar" <viresh.linux@gmail.com>,
	"Karol Lewandowski" <k.lewandowsk@samsung.com>,
	"Jiri Kosina" <jkosina@suse.cz>,
	STEricsson <STEricsson_nomadik_linux@list.st.com>,
	"Joe Perches" <joe@perches.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Alessandro Rubini" <rubini@unipv.it>,
	linuxppc-dev@lists.ozlabs.org,
	"Alexander Stein" <alexander.stein@systec-electronic.com>
Subject: Re: [PATCH] i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls
Date: Mon, 18 Feb 2013 12:35:15 +0200	[thread overview]
Message-ID: <20130218103515.GJ20771@intel.com> (raw)
In-Reply-To: <1360970315-32116-1-git-send-email-dianders@chromium.org>

On Fri, Feb 15, 2013 at 03:18:35PM -0800, Doug Anderson wrote:
> There is simply no reason to be manually setting the private driver
> data to NULL in the remove/fail to probe cases.  This is just extra
> cruft code that can be removed.
> 
> A few notes:
> * Nothing relies on drvdata being set to NULL.
> * The __device_release_driver() function eventually calls
>   dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
>   twice.
> * I verified that there were no cases where xxx_get_drvdata() was
>   being called in these drivers and checking for / relying on the NULL
>   return value.
> 
> This could be cleaned up kernel-wide but for now just take the baby
> step and remove from the i2c subsystem.
> 
> Reported-by: Wolfram Sang <wsa@the-dreams.de>
> Reported-by: Stephen Warren <swarren@wwwdotorg.org>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
>  drivers/i2c/busses/i2c-au1550.c             | 1 -
>  drivers/i2c/busses/i2c-bfin-twi.c           | 2 --
>  drivers/i2c/busses/i2c-cpm.c                | 2 --
>  drivers/i2c/busses/i2c-davinci.c            | 2 --
>  drivers/i2c/busses/i2c-designware-pcidrv.c  | 2 --
>  drivers/i2c/busses/i2c-designware-platdrv.c | 2 --

For i2c-designware-pcidrv.c and i2c-designware-platdrv.c:

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>