On Tue, 2005-02-08 at 15:32, Alan Stern wrote:
> A few details would help, such as the contents of /proc/bus/usb/devices 
> and a system log with CONFIG_USB_DEBUG turned on.
> 

Sorry for the delay. I had some hard disk problems.

OK, so I compiled a kernel with CONFIG_USB_DEBUG on, installed ehci_hcd
with debug=2, and ran my camera driver modified to attempt 40 fps reads
from the camera in 800x600 pixel mode, 8 bits per pixel.

I get wedged as usual and I have to "kill -9" my viewer program from
elsewhere in order to rescue the situation.

However, I also get no messages in /var/log/messages and nothing from
the output of 'dmesg' either. What did I miss?


Meanwhile, I ran my driver with detailed debugging of its own and what I
see is like this:

....
Receive 32768 bytes from camera: add it to the image-buffer
Resubmit URB
Receive 32768 bytes from camera: add it to the image-buffer
Resubmit URB
Receive 20667 bytes from camera: add it to the image-buffer (that marks
the end of frame). This URB has been composed from 41 full 512 byte
bulk-packets plus one half-filled 512 byte bulk-packet.
Resubmit URB

[no more IRQs hit my callback function over the next tenth of a second]

The timebomb goes off.
Tell the camera to stop streaming.
Release all URBs.

This is as close as I can get to diagnostics, since I don't have useful
access to the next layer down.

Steve



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