Hi Hans, On Friday 11 January 2013 12:48:19 Hans Verkuil wrote: > On Mon January 7 2013 20:56:07 Laurent Pinchart wrote: > > On Monday 07 January 2013 13:09:47 Hans Verkuil wrote: > > > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > > > > The documentation of the error_idx field was incomplete and confusing. > > > This patch improves it. > > > > > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > --- [snip] > > I think some flexibility should still probably be left to drivers (and I'm > > not talking about UVC here), as some drivers might not be able to know > > that a control is write-only before trying to read it and getting an > > error. > > Well, if drivers don't know if a control is e.g. write-only until they try > it, then it can't be done during pre-validation anyway, so that's no > problem. Sure, but my point is that we don't want to enforce in the spec that those checks must always be done during pre-validation, otherwise drivers that can't do it will violate the spec. > The pre-validation should at minimum check whether ctrl_class is set up > correctly, whether all controls in the list actually exist, and check > against READ_ONLY or WRITE_ONLY (if known upfront). > > The v4l2-compliance tool will test those minimum checks. > > The control framework will also check whether the GRABBED flag is set for > a control and if the new value of a control is valid. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
