DM365: Unable to read from /dev/video0 (kernel 2.6.37)

hello everyone,

I've just finished building a FileSystem+Kernel Image from arago, with kernel linux-davinci-2.6.37-psp03.21.00.04.sdk-r57.

everything seems to be working, aside from one problem: v4l2 isn't working

 

every time I try to run dmai/ce example / gstreamer pipeline / manually read from /dev/video0 I'm getting the following error:

invalid media connection to video node
invalid external subdev

 

My bootargs are:

console=ttyS0,115200n8 noinitrd rw ip=192.168.1.2 root=/dev/nfs nfsroot=192.168.1.1:/home/user/workdir365/rootfs,nolock mem=60M video=davincifb:vid0=OFF:vid1=OFF:osd0=720x576x16,4050K dm365_imp.oper_mode=0 davinci_capture.device_type=1 davinci_display.cont2_bufsize=6291456 vpfe_capture.bufsize=829440davinci_enc_mngr.ch0_mode=pal vpfe_capture.interface=0

 

dmesg after boot:

5875.log2.txt

 

I've looked in the kernel sources and it looks like the failure occurs in vpfe_video.c, but I have no idea why any function there would fail since tvp5146 was registered OK

 

any help would be great!

Thanks,

         James

6 Replies

  • James,

    VPFE Capture driver you are using is based on media controller framework. I believe gstreamer has not incorporated necessary changes needed yet because of the advanced framework. So, it is failing. I suggest you to check these sample applications( SDK also should contain them) for the driver you are using - http://arago-project.org/git/projects/?p=examples-davinci.git;a=shortlog;h=refs/heads/03.21.00.03

     

    Regards,

    Nagabhushana


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  • In reply to Nagabhushana:

    Hello Nagabhushana,

     

    I've tried running the vpif examples from the git you provided (compiled them against my Arago kernel), and I got the same error messages

     

    I also provide the kernel config (this is the default, I haven't touched it, but perhaps something is missing):

    6232.conf.txt.

     

    Any ideas?

     

    Best regards,

            James

     

  • In reply to James Brown:

    You should use applications under mc/dm365 as they are intended for dm365. VPIF applications are only for omapl138 platform.

    Regards,

    Nagabhushana


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  • In reply to Nagabhushana:

    The test applications are indeed working, so this is a gstreamer-specific problem.

    Is there an ETA until the needed changes will make it into gstreamer / instructions how to insert the changes myself?

     

     

  • In reply to James Brown:

    Nice to hear that applications are working for you.

    Media-controller framework is not part of linux up-stream. Efforts are ON to make the same possible. So, it will take some time. Regarding making gstreamer changes yourself, http://en.wikipedia.org/wiki/GStreamer might help.

    Regards,

    Nagabhushana


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  • I'm seeing the message" invalid media connection to video node" and "invalid external subdev" on 2.6.37 kernel also.  I think this is due to the mediabus api added to that version of the kernel.  It may be necessary to set up the /dev/media0 device first before /dev/video0 can be used.  For more info, see: http://processors.wiki.ti.com/index.php?oldid=56675