After some trial and error, I got my Conceptronic CHVIDEOCR working on my linux desktop machine. This device is using module em28xx, with configuration card=9 and device type 1b80 e34e in /sys/bus/usb/drivers/em28xx/new_id modprobe em28xx card=9 echo 1b80 e34e > /sys/bus/usb/drivers/em28xx/new_id
Once this is done, /dev/video0 device is created and can be used by my capture application, for example mplayer: mplayer tv:// -tv driver=v4l2:width=320:height=240
My desktop computer is runing kernel "184.108.40.206 #8 SMP PREEMPT Thu Jan 28 10:51:16 CET 2010 i686 GNU/Linux" as reported from uname
I have followed the same steps in my overo air board, and the /dev/video0 device is created as expected, however, mplayer only shows a green image, after a while it crashes ginig the following messages:
I suspect that the application is only receiving 0's, so I somehow modify the v4l2 capture application example, to show the data comming from the capturer. The result is possitive, only zeros comming from the driver. Also, once it crashes giving error "em28xx #0: cannot change alternate number to 0 (error=-110)". I cannot use the device until a reset is performed.
Overo kernel is "Linux overo 2.6.32 #1 Tue Apr 13 19:15:51 CEST 2010 armv7l GNU/Linux"
Finally I have also tried the same procedure for a Logitech usb webcam (rightsound2?) which uses module "gspca_zc3xx". This works ok, both in my desktop and in overo board.
- Do you have any experience on these issues? - Do you know if this could be related to kernel compilation directives / DMA access or some other configuration? - Could be this an ARM - OMAP specific problem?
This is the code I have used to see whether there is someting being sent:
/* * V4L2 video capture example * * This program can be used and distributed without restrictions. */