On Fri March 15 2013 14:58:35 Mauro Carvalho Chehab wrote: > Em Fri, 15 Mar 2013 11:27:23 +0100 > Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > > > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > > This ioctl is defined as IOW, so pass the argument by value instead of by > > reference. I could have chosen to add const instead, but this is 1) easier > > to handle in drivers and 2) consistent with the s_std subdev operation. > > Hmm... this could potentially break userspace. I remember I saw in the past > some code that used the returned standard. I can't remember where. It could > be inside the V4L1 compat layer, but I think it was on some userspace app(s). > > Had you verify how the several different userspace apps handle S_STD? video_usercopy doesn't call copy_to_user for write-only ioctls, so any changed data will never make it to userspace. If there is an app that expects to see the returned standard then they broke many years ago :-) Regards, Hans -- 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
