Re: [PATCH 12/24] media/video: fix dangling pointers

[Wolfram Sang <w.sang@pengutronix.de>]

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> > > Personally I'd much rather just not bother setting the driver data in
> > > the removal path, it seems unneeded.  I had assumed that the subsystem
> > > code cared for some reason when I saw the patch series.
> > 
> > Anyway, should this really be necessary, then for the media drivers this
> > should be done in v4l2_device_unregister_subdev() and not in every driver.
> > 
> > But this just feels like an i2c core thing to me. After remove() is called
> > the core should just set the client data to NULL. If there are drivers that
> > rely on the current behavior, then those drivers should be reviewed first as
> > to the reason why they need it.
> 
> I tend to agree, now.
> 
> Wolfram, how do you feel about this? I feel a little sorry that I more
> or less encouraged you to submit this patch series, and now I get to
> agree with the objections which were raised against it.

Well, this is a valuable outcome in my book. Maybe seeing the actual amount of
modifications necessary for cleaning up clientdata helped the process. While
working on it, I also got the impression that it should be handled differently
in the future, of course. Although I was thinking of something different
('i2c_(allocate|free)_clientdata' as mentioned before), I prefer the above
proposal as it is most simple.

> My key motivation was that I wanted i2c_set_clientdata() to be called
> before kfree(). Now that everybody seems to agree that the latter
> belongs to the drivers while the former belongs to lower layers
> (i2c-core or even driver core), this is not going to happen. So I guess
> we want to remove calls to i2c_set_clientdata(NULL) from all drivers
> and have only one in i2c-core for now?

Fine with me. Let me know if I can assist you with the series.

Regards,

   Wolfram

-- 
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