Hi Sylwester, On Fri, Apr 12, 2019 at 01:14:38PM +0200, Sylwester Nawrocki wrote: > On 4/12/19 12:32, Hans Verkuil wrote: > > On 4/12/19 12:16 PM, Sylwester Nawrocki wrote: > >> On 4/12/19 11:20, Boris Brezillon wrote: > >>> The fimc-isp-video.c and fimc-lite.c were missing the > >>> V4L2_CAP_VIDEO_CAPTURE_MPLANE flag when reporting device caps. > >> > >> Th omission was intentional, as these video nodes cannot be used > >> by "standard" V4L2 capture applications. Some sub-devices need to > >> be configured first in order to use these video nodes. It was > >> agreed to not set these capabilities in the driver, instead user > >> space library, e.g. libv4l2 with driver-specific plugin handling > >> the media controller and v4l2 subdev calls would set the capability > >> for the applications. Has something changed? > > > > I remember that this was discussed, but nobody actually followed that > > guideline. Just do: > > > > git grep -l V4L2_CAP_VIDEO_CAPTURE drivers/media/platform > > > > It really doesn't make sense to leave it out since userspace has to know if > > it is single or multiplanar, and if you don't set this capability, then how > > can it tell? > > Presumably you can't by only querying the video device, this would require > MC and driver-specific user space. > > > I always thought we need a separate CAP or some other way of signaling this, > > but the few times I proposed something it was always shot down. > > > > So to be consistent with the other MC drivers you should set this MPLANE cap > > as well in the fimc driver. > > I'm not against the $subject patch, rather the opposite. Especially if > it is a part of reasonable API updates. But removing the capabilities was > actually a requirement to get the driver merged, not a guideline. > And was rather painful then, now the driver is probably not in use any more > so I don't really mind. As this driver is quite old I assume there's little interest in investing in it, but is there any chance Samsung would be interested in contributing to libcamera for newer generations ? :-) -- Regards, Laurent Pinchart
