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

[Steve Longerbeam]

On 02/01/2017 01:30 AM, Philipp Zabel wrote:
> 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.

Ah, yep, this is a bug. Need to modify the capture device's
width/height at .set_fmt() in the subdev's device-node source
pad (csi and prpenc/vf).

> > 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

Ah cool, I wasn't aware media-ctl did this, but it makes sense and
makes it easier on the user.

Steve

> > > 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