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SubjectRe: [PATCH] base: dd: don't remove driver_data in -EPROBE_DEFER case
On Tue, May 03, 2016 at 03:11:26PM +0200, Thierry Reding wrote:
> On Tue, Mar 08, 2016 at 11:15:22PM +0800, Yi Zhang wrote:
> > the driver_data may be used for sanity check, it fails the
> > probe() if driver_data is NULL after it is re-triggered.
> > for example, soc_probe() in sound/soc/soc-core.c
> >
> > Signed-off-by: Yi Zhang <yizhang_hust@163.com>
> > ---
> > drivers/base/dd.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Hi Greg,
>
> This causes a boot regression on at least one board, caused by one of
> the drivers looking at driver data to check whether or not the driver
> has properly loaded. If the code encounters a non-NULL pointer it
> tries to dereference it, but because it's already been freed there is
> no memory backing it and things crash.
>
> I don't think keeping stale pointers around is a good idea. The whole
> point of setting this to NULL in the core is so that probe failures
> result in the same starting conditions no matter what.
>
> Can we please get this reverted?
>
> Cc'ing linux-tegra for visibility since that's where the boot regression
> is observed.

Now reverted, thanks for letting me know.

greg k-h

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