kernel 2.4.37 usb acm hard lockup

[duane]

Hello, I have a linux-2.4.37 - kernel *HANG* hard lockup that I am
trying to debug, ctl-alt-del does not fix the problem. The problem does
not occur on current 2.6 kernels.

Specifically the device I am talking to is an USB-ACM type 'scanner'
type device, it shows up as a USB com port /dev/input/ttyACM0 - and I
read/write commands to & from the device.

Some fixes have already been back ported from 2.6 (trying to get it to
run on 2.4.20-8 [rh9]) and I'm not getting far and asking for some help
or some pointers where to go next.

The bug is quite reproducible - I have a small C program, and a small
shell script loop. It sends a few commands (ie: initialize, scan and
transmit image) then saves the image to a file.  Somewhere between 70 to
150 scans BANG a hard hang occurs, takes between 5 to 15 minutes.

I get *NO* output on the console, like an oops or something like that.
Only debug messages I have added in my program.

I have already turned the USB KERNEL debug messages on in the .config
file, and I have "dmesg -n 9".

And - if I do add too many of my own debug messages, depending on the
volume of messages the problem takes longer to appear or goes away (I
give up after several hours) - which makes me think it is a timing/race
condition :-(

If this is the wrong list, or there is a better list for this specific
2.4/usb/acm problem please let me know, I don't really know where else
to ask.

Thanks.

-Duane.







--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/