Re: [PATCH 01/14] v4l2-ioctl.c: OR flags in v4l_fill_fmtdesc(), not don't overwrite

[Philipp Zabel <p.zabel@pengutronix.de>]

On Wed, 2019-07-24 at 15:30 +0200, Hans Verkuil wrote:
> On 7/24/19 3:22 PM, Philipp Zabel wrote:
> > On Wed, 2019-07-24 at 13:05 +0200, Hans Verkuil wrote:
> > > If a driver sets a FMT flag in the enum_fmt op, then that will be
> > > ignored since v4l_fill_fmtdesc() overwrites it again.
> > > 
> > > v4l_fill_fmtdesc() should OR its flag, not overwrite it.
> > > 
> > > Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> > > ---
> > >  drivers/media/v4l2-core/v4l2-ioctl.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > index 80efc581e3f9..911a20f915c5 100644
> > > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > @@ -1390,7 +1390,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > >  
> > >  	if (descr)
> > >  		WARN_ON(strscpy(fmt->description, descr, sz) < 0);
> > > -	fmt->flags = flags;
> > > +	fmt->flags |= flags;
> > >  }
> > >  
> > >  static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
> > 
> > If the enum_fmt op does not write fmt->flags, will it not contain the
> > value provided by userspace at this point? I think p->flags must be
> > cleared in v4l2_enum_fmt() with this change, before the enum_fmt op is
> > called.
> 
> All fields after 'type' in struct v4l2_fmtdesc are cleared by the core:
> search for INFO_FL_CLEAR(v4l2_fmtdesc, type) in v4l2-ioctl.c.
> 
> So 'flags' is already zeroed when this function is called.

Got it, thanks. In that case,

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp