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

James Brown

Other Parts Discussed in Thread: TVP5146, OMAPL138

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

over 12 years ago

0 Nagabhushana over 12 years ago

TI__Expert 4685 points

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

0 James Brown over 12 years ago in reply to Nagabhushana

Prodigy 40 points

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

0 Nagabhushana over 12 years ago in reply to James Brown

TI__Expert 4685 points

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

0 James Brown over 12 years ago in reply to Nagabhushana

Prodigy 40 points

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?

0 Nagabhushana over 12 years ago in reply to James Brown

TI__Expert 4685 points

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.

0 Pete Eberlein over 12 years ago

Intellectual 580 points

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

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