Hi, On Wed, Mar 19, 2003 at 06:06:48AM +0100, Paul Stravers wrote: > Below follows an excerpt of the debug output from scanner.c and > uhci-debug.c. To avoid cluttering this mailing list with debug > information I have put the complete syslog on the web at > http://www.oink-oink-oink.net/usb-problem/syslog2.gz (269 kB).
I think I know the reason for this problem. It's most probably in scanner.c. There has been some discussion some months ago if the code in read of scanner.c is correct. I think it's incorrect but some other people didn't seem to share that view.See below for details. > The USB subsystem freezes. Sometimes I can solve it with "rmmod > usb-uhci" but usually I have to reboot to get the USB subsystem to work > again. The good news is that the part of the system that does not depend > on USB keeps running, so I can login on a console and type "reboot". That's houldn't happen anyway. I'm not yet sure if that freeze happens in the scanner driver or the uhci driver. > Did that, the problem persists with 2.4.21-pre5. I changed the timeout > in write_scanner to 600*HZ and I enabled debugging. At the end of this > mail I am including messages from syslog . It's not related to write but read and it's not a timeout problem. > > Does SANE work instead of vuescan? Or do you get the same timeouts? I > > don't know if that's the same scanner but a "Nikon LS 40 ED" is listed > > as supported device. You can use current versions of sane with libusb > > instead of the kernel scanner driver. If it works with libusb but not > > the kernel driver we know who is to blame :-) > > I downloaded SANE and got the "coolscan2" backend to work with my Nikon > LS-40. However, I could not operate it in a way that produced usable > pictures, still looking for a GUI frontend that supports coolscan2. scanimage supports all the options that the coolscan2 backend provides. It's just a bit hard to use :-) Any SANE frontend should work with the coolscan2 backend (and any other backend). I'm pretty sure that at least xsane works. Maybe you have tow versions of sane-backends and xsane still uses the old one? > I noticed however that typing Ctl-C to the "scanimage" frontend > produced the familiar "usb_control/bulk_msg: timeout" messages in the > syslog... Maybe the same issue. Let's see what happens: > Mar 18 07:02:26 kletskop kernel: scanner.c: read stats(0): result:0 this_read:32768 > partial:21224 count:42448 We want to read 42448 bytes. The buffer size is 32768 so that's the maximum we can do in one turn. The scanner returns only 21224 bytes (probably one scan line). So far that's ok. Now the error occurs. > Mar 18 07:02:26 kletskop kernel: scanner.c: read stats(0): result:-75 this_read:9680 > partial:9680 count:9680 The reason is that the next read reads only 9680 bytes instead of 21224. The scanner doesn't seem to be able to handle this. In my opinion the calculation count -= this_read; /* Compensate for short reads */ is just wrong. That should be count -= partial; Try to change that in scanner.c, around line 710. Bye, Henning ------------------------------------------------------- This SF.net email is sponsored by: Does your code think in ink? You could win a Tablet PC. Get a free Tablet PC hat just for playing. What are you waiting for? http://ads.sourceforge.net/cgi-bin/redirect.pl?micr5043en _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
