On Sunday 29 March 2009 11:35:45 Mauro Carvalho Chehab wrote: > On Sun, 29 Mar 2009 11:06:19 +0200 > > Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > > On Sunday 29 March 2009 10:50:02 Patch from Trent Piepho wrote: > > > The patch number 11260 was added via Trent Piepho > > > <xyzzy@xxxxxxxxxxxxx> to http://linuxtv.org/hg/v4l-dvb master > > > development tree. > > > > > > Kernel patches in this development tree may be modified to be > > > backward compatible with older kernels. Compatibility modifications > > > will be removed before inclusion into the mainstream Kernel > > > > > > If anyone has any objections, please let us know by sending a message > > > to: Linux Media Mailing List <linux-media@xxxxxxxxxxxxxxx> > > > > > > ------ > > > > > > From: Trent Piepho <xyzzy@xxxxxxxxxxxxx> > > > v4l2-ioctl: Check format for S_PARM and G_PARM > > > > > > > > > Return EINVAL if VIDIOC_S/G_PARM is called for a buffer type that the > > > driver doesn't define a ->vidioc_try_fmt_XXX() method for. Several > > > other ioctls, like QUERYBUF, QBUF, and DQBUF, etc. do this too. It > > > saves each driver from having to check if the buffer type is one that > > > it supports. > > > > Hi Trent, > > > > I wonder whether this change is correct. Looking at the spec I see that > > g/s_parm only supports VIDEO_CAPTURE, VIDEO_OUTPUT and PRIVATE or up. > > > > So what should happen if the type is VIDEO_OVERLAY? I think the > > g/s_parm implementation in v4l2-ioctl.c should first exclude the > > unsupported types before calling check_fmt. > > Makes sense to me. > > > I also wonder whether check_fmt shouldn't check for the presence of the > > s_fmt callbacks instead of try_fmt since try_fmt is an optional ioctl. > > One developer suggested to merge try_fmt and s_fmt into one callback. > IMO, this makes sense, since I have the feeling that this will simplify > the code a little bit on the drivers. If we go this way, then we can > check for the new try_s_fmt callback. I agree with this. It's also easy to gradually migrate to such a new callback since it is probably quite difficult to do this in one big bang patch. Regards, Hans -- Hans Verkuil - video4linux developer - sponsored by TANDBERG -- 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
