Re: [PATCH v3 00/24] i.MX Media Driver

[Philipp Zabel]

On Tue, 2017-01-31 at 17:26 -0800, Steve Longerbeam wrote:
[...]
> > # Set pad formats
> > media-ctl --set-v4l2 "'tc358743 1-000f':0[fmt:UYVY/1920x1080]"
> > media-ctl --set-v4l2 "'imx6-mipi-csi2':1[fmt:UYVY2X8/1920x1080]"
> > media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY2X8/1920x1080]"
> > media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/1920x1080]"
> >
> > v4l2-ctl -d /dev/video4 -V
> > # This still is configured to 640x480, which is inconsistent with
> > # the 'ipu1_csi0':2 pad format. The pad set_fmt above should
> > # have set this, too.
> 
> Because you've only configured the source pads,
> and not the sink pads. The ipu_csi source format is
> dependent on the sink format - output crop window is
> limited by max input sensor frame, and since sink pad is
> still at 640x480, output is reduced to that.

No, it is set (see below). What happens is that capture_g_fmt_vid_cap
just returns the capture devices' priv->vdev.fmt, even if it is
incompatible with the connected csi subdevice's output pad format.

priv->vdev.fmt was never changed from the default set in
imx_media_capture_device_register, because capture_s/try_fmt_vid_cap
were not called yet.

> Maybe I'm missing something, is it expected behavior that
> a source format should be automatically propagated to
> the sink?

media-ctl propagates the output pad format to all remote subdevices'
input pads for all enabled links:

https://git.linuxtv.org/v4l-utils.git/tree/utils/media-ctl/libv4l2subdev.c#n693

> > v4l2-ctl --list-formats -d /dev/video4
> > # This lists all the RGB formats, which it shouldn't. There is
> > # no CSC in this pipeline, so we should be limited to YUV formats
> > # only.
> 
> right, need to fix that. Probably by poking the attached
> source subdev (csi or prpenc/vf) for its supported formats.

You are right, in bayer/raw mode only one specific format should be
listed, depending on the CSI output pad format.

regards
Philipp