Johannes Meixner <jsm...@suse.de> writes: > Hello,
Hi! > On Dec 15 16:27 Olaf Meeuwissen wrote (shortened): >> Working on support for a new business oriented all-in-one for iscan, I >> have hit a dead end and would appreciate some insights/suggestions. >> >> When attaching the device, the kernel loads the usblp module and CUPS >> has no trouble finding the printer part. On the scanner side however, >> the device is (usually) found but I can't get it to scan. > > I have no knowledge how the USB mess is supposed to work > but perhaps issue "D)" in > https://bugzilla.novell.com/show_bug.cgi?id=184798 > might be about the same problem? That looks like it might be about the same or at least very similar problem. Thanks for the link. >> Considering the target audience for this device, I can't very well say >> "Oh, just rmmod usblp before you scan and insmod usblp again when you >> are done". > > As far as I know this is exactly what the USB stuff in the > current kernels requires. > > >> Similarly, suggesting to compile a CUPS usb backend using >> usb-libusb.c[1] is also not particularly user friendly. > > No ;-) > As far as I know the only solution with the current kernels > is that the CUPS usb backend uses libusb out of the box. > > >> Is there a way to get SANE, CUPS and usblp to play nice _together_? > > As far as I know with the current kernels: No. > > > But perhaps I am totally wrong and the issue is only because > usblp and libusb try to communiucate with the same USB endpoint > (i.e. with the whole all-in-one device) instead of usblp > communicates only with the USB endpointwhitch matches to > the printer interface of the device and libusb communicates > only with the USB endpoint whitch matches to the scanner interface > of the device (as far as I know all Epson all-in-one devices provide > seperated USB interfaces for the printer unit and the scanner unit). > But I don't know if such a kind of seperated communication is > possible at all with the current kernels. No, both usblp and libusb (try to) talk to different endpoints. As matter of fact, I tried with a little test program that explicitly claims the interface with the scanner endpoints. I even recompiled my kernel with USB debugging support to see that usblp claims the interface with the printer endpoints. The odd thing is that for a number of other all-in-ones, usblp does not seem to be (such) a problem. Thanks for the info. -- Olaf Meeuwissen EPSON AVASYS Corporation, SE1 FSF Associate Member #1962 sign up at http://member.fsf.org/ GnuPG key: 6BE37D90/AB6B 0D1F 99E7 1BF5 EB97 976A 16C7 F27D 6BE3 7D90 Penguin's lib! -- I hack, therefore I am -- LPIC-2
