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 ? Best 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
