Hi, On Tue, Jun 17, 2003 at 10:26:08PM +0100, Major A wrote: > > I'll try to summarize the problem (copied from a mail to > > linux-usb-users): > > > > | We want to read 42448 bytes (e.g. two scan lines). 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. > > | > > | 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. > > > > So the scanner doesn't seem to like reads different from the size of > > one scan line (?). I gueess the backend shouldn't try to read more > > than the scanner is able to return. > > Ah, OK, but Coolscan2 strictly tries to read one scanline at the > time. On the LS-40, this is a maximum of 23328 bytes (2916 pixels, 4 > channels each, 2 bytes per channel), which is less than 32k.
Ok. I was talking about a log created by vuescan: Mar 18 07:02:26 kletskop kernel: scanner.c: read stats(0): result:0 this_read:32768 partial:21224 count:42448 Mar 18 07:02:26 kletskop kernel: uhci.c: uhci_result_interrupt/bulk() failed with status 500000 [...] Mar 18 07:02:26 kletskop kernel: scanner.c: read stats(0): result:-75 this_read:9680 partial:9680 count:9680 Mar 18 07:02:26 kletskop kernel: scanner.c: read_scanner(0): funky result:-75. Consult Documentation/usb/scanner.txt. Mar 18 07:02:36 kletskop kernel: usb_control/bulk_msg: timeout I remember similar reports about SANE but can't find a log at the moment. Hint for the bug reporter: A kernel logfile would be nice. For that, enable USB debugging in make menuconfig (probably already enabled) and debug messages in drivers/usb/scanner.h. This way we can see what's exactly going on. > > The Nikon Coolscan 4 seems to be the only scanner with this problem. > > At least that's the only one I ever got reports for. So I really think > > it's either a scanner or backend problem. > > Hmmm, that would be me... the scanner is a bit silly in the way that > it tunnels SCSI commands across USB in a proprietary way, but it seems > to work great in most cases, so it's probably not a hardware fault. Maybe it just doesn't like "half-sent" buffers. On the other hand, if you don't send more than one scan line I really don't know what's wrong. > > By the way: The problem with coolscan/kernel scanner driver seems to > > happen (have happened?) also with vuescan. Looks like a similar > > scanning routine is used. > > That's right. VueScan also uses (used?) the scanner module, so go > figure... But vuescan does read more than 32k at once. At least that what's the log shows. Maybe it's a different problem? Bye, Henning
