i.MX6 MIPI-CSI2 OV5640 Camera testing on Mainline Linux

[Adam Ford]

On Tue, Oct 23, 2018 at 11:36 AM Steve Longerbeam
<steve_longerbeam at mentor.com> wrote:
>
> Hi Adam,
>
> On 10/23/18 8:19 AM, Adam Ford wrote:
> > On Mon, Oct 22, 2018 at 7:40 AM Fabio Estevam <festevam at gmail.com> wrote:
> >> Hi Adam,
> >>
> >> On Mon, Oct 22, 2018 at 9:37 AM Adam Ford <aford173 at gmail.com> wrote:
> >>
> >>> Thank you!  This tutorial web site is exactly what I need.  The
> >>> documentation page in Linux touched on the media-ctl links, but it
> >>> didn't explain the syntax or the mapping.  This graphical
> >>> interpretation really helps it make more sense.
> >> Is capturing working well on your i.MX6 board now?
> > Fabio,
> >
> > Unfortunately, no.  I built the rootfs based on Jagan's instructions
> > at https://openedev.amarulasolutions.com/display/ODWIKI/i.CoreM6+1.5
> >
> > I tried building both the 4.15-RC6 kernel, a 4.19 kernel and a 4.14 LTS kernel.
> >
> > Using the suggested method of generating the graphical display of the
> > pipeline options, I am able to enable various pipeline options
> > connecting different /dev/videoX options tot he camera.  I have tried
> > both the  suggested method above as well as the instructions found in
> > Documentation/media/v4l-drivers/imx.rst for their respective kernels,
> > and I have tried multiple options to capture through
> > ipu1_csi1_capture, ipu2_csi1_capture, and ip1_ic_prepenc capture, and
> > all yield a broken pipe.
> >
> > libv4l2: error turning on stream: Broken pipe
> > ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could
> > not read from resource.
> > Additional debug info:
> > gstv4l2bufferpool.c(1064): gst_v4l2_buffer_pool_poll ():
> > /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
> > poll error 1: Broken pipe (32)
> >
> > I can hear the camera click when I start gstreamer and click again
> > when it stops trying to stream.
> >
> > dmesg indicates a broken pipe as well..
> >
> > [ 2419.851502] ipu2_csi1: pipeline start failed with -32
> >
> > might you have any suggestions?
>
>
> This -EPIPE error might mean you have a mis-match of resolution, pixel
> format, or field type between one of the source->sink pad links. You can
> find out which pads have a mis-match by enabling dynamic debug in the
> kernel function __media_pipeline_start.

Following Jagan's suggestion, I tried to make sure all the resolution
and pixel formats were set the same between each source and sink.

media-ctl --set-v4l2 "'ov5640 2-0010':0[fmt:UYVY2X8/640x480
field:none]"
media-ctl --set-v4l2 "'imx6-mipi-csi2':1[fmt:UYVY2X8/640x480
field:none]"
media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY2X8/640x480
field:none]"
media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/640x480 field:none]"

>
> Also make sure you are attempting to stream from the correct /dev/videoN.

I have graphically plotted the pipeline using media-ctl --print-dot
and I can see the proper video is routed, but your dynamic debug
suggestion yielded something:

   imx-media capture-subsystem: link validation failed for 'ov5640
2-0010':0 -> 'imx6-mipi-csi2':0, error -32

I am assume this means the interface between the camera and the csi2
isn't working.  I am going to double check the power rails and the
clocks.  i can hear it click when activated and deactivated, so
something is happening.

adam

>
> Steve
>