On Wednesday 18 February 2009 15:51:32 Laurent Pinchart wrote: > Hi Gilles, > > On Thursday 12 February 2009 23:44:55 gilles wrote: > > Hi everyone, > > Sorry for double posting, but I originally sent this to the old mailing > > list. Here it is: > > > > I have a couple of comments / suggestions regarding the part on > > controls of the V4L2 api: > > Some controls, such as pan relative and tilt relative are write-only, > > and reading their value makes little sense. Yet, there is no way of > > knowing about this, but to try and read a value and be greeted with > > EINVAL or similar. There is already a read-only flag > > (V4L2_CTRL_FLAG_READ_ONLY) in struct v4l2_query. Does it make sense to > > add another one for write-only controls ? > > Yes it does. Martin Rubli from Logitech sent a mail in April 2008 to the > video4linux mailing list. Search the list archives for "[PATCH] Support > for write-only controls". Feel free to submit a patch. > > > The extended controls Pan / Tilt reset are defined in the API as > > boolean controls. Shouldnt these be defined as buttons instead, as they > > dont really hold a state (enabled/disabled) ? > > Agreed. As no driver seem to be using those controls yet, it should be > safe to update the spec. Could you submit a patch ? Hi Gilles, Laurent, I will take care of this. I have to do some doc updates relating to controls anyway, so it's easy for me to add this as well. 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
