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. -- Regards, Sylwester
