Re: [PATCH] drivers-core: nullify private pointer on device-release

[Greg KH <greg@kroah.com>]

On Mon, Oct 05, 2009 at 06:14:37PM +0200, Guennadi Liakhovetski wrote:
> On Mon, 5 Oct 2009, Greg KH wrote:
> 
> > On Mon, Oct 05, 2009 at 10:11:50AM +0200, Guennadi Liakhovetski wrote:
> > > On Thu, 1 Oct 2009, Greg KH wrote:
> > > 
> > > > On Thu, Oct 01, 2009 at 03:45:56PM +0200, Guennadi Liakhovetski wrote:
> > > > > On Thu, 1 Oct 2009, Greg KH wrote:
> > > > > 
> > > > > > On Thu, Oct 01, 2009 at 10:02:08AM +0200, Guennadi Liakhovetski wrote:
> > > > > > > Device structures can be reused over multiple device_add / device_release 
> > > > > > > cycles.
> > > > > > 
> > > > > > They shouldn't be as they should be dynamic, not static.
> > > > > 
> > > > > Should they? I'm pretty sure this is not the first time this comes up - 
> > > > > there are several drivers and / or subsystems, that re-use driver objects. 
> > > > 
> > > > Then those drivers and subsystems should be fixed, as that is incorrect.
> > > > 
> > > > > But finding in mail archives wouldn't be very easy. And it worked until 
> > > > > now - why should we break it?
> > > > 
> > > > I would argue that this code was always broken.
> > > > When did this problem show up for you?
> > > 
> > > Since commit b4028437876866aba4747a655ede00f892089e14
> > 
> > Again, which driver/devices are having this problem?
> 
> Quoting my previous reply in this thread:
> 
> > > What device is having this problem?
> > 
> > My problem case is the soc-camera framework. There device struct is 
> > embedded into the video client object, which are kept as long as the 
> > driver is loaded.
> 
> </quote>

Ok, then that code needs to be fixed :)

> > The patch
> > referenced above had been in linux-next for almost 6 months with no
> > reported problems, so this is news to me :)
> 
> Hm, really 6 months in linux-next? That surprises me too, that I didn't 
> notice it until now. But in any case, the aforementioned commit introduced 
> a regression. If you disagree, that it has to be fixed centrally as per 
> proposed patch, no problem, I'm pushing a patch tonight, that will fix 
> this for soc-camera. No idea about other drivers.

Great, glad to see this being fixed where it should be.  As no one else
has reported a problem, I'm guessing that this is the only incorrect
code.

thanks,

greg k-h