Messages in this thread | | | Date | Fri, 20 May 2011 10:01:14 +0200 | From | Uwe Kleine-König <> | Subject | Re: [22/44] driver core: let dev_set_drvdata return int instead of void as it can fail |
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On Fri, May 20, 2011 at 02:53:30AM -0500, Milton Miller wrote: > On Fri, 20 May 2011 about 00:10:40 -0000, Greg Kroah-Hartman wrote: > > > > From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > > > > Before commit > > > > b402843 (Driver core: move dev_get/set_drvdata to drivers/base/dd.c) > > > > calling dev_set_drvdata with dev=NULL was an unchecked error. After some > > discussion about what to return in this case removing the check (and so > > producing a null pointer exception) seems fine. > > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > > Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> > > > > I obviously didn't follow the discussions close enough and got > confused[1], but I don't like the anticipated fallout of pushing this > change though all the drivers. Let alone see the arguments that not > being able to free the device when it fails is no reason to fail. > > So, my first question is: When is it legal for a driver to set driver > data before a device is registered? A driver cannot set driver data on an unregistered device because it doesn't get it's hands on it before. So it's only the code that registers a device that has a chance to do so.
A while back I thought about breaking these constructs by setting driver_data to NULL before a device is handed to a driver. Never came around to make a patch tough.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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