El Mon, 16 de Apr de 2007, a las 02:50:01PM +0200, Gerhard Jaeger dijo: > On Montag, 16. April 2007, JKD wrote: > [SNIPSNAP] > > > This is also an issue with the Plustek backend, reported by various > > > Ubuntu and Gentoo users. As already stated by PhobosK, the problem is > > > the kernel option CONFIG_USB_SUSPEND. This in deed is needed for laptop > > > users. It is currently marked as "experimental" but already used by > > > various > > > distros. > > > > > > > That was my first thought. But if it's a kernel problem neither xsane > > nor scanimage would scan successfully. And in two different compilations of > > hp3900, ubuntu's one fails and my last compilation works. > > > > > I think the problem really is, that libusb does not know anything about > > > that > > > suspend stuff and therefore we have more or less no possibility to wakeup > > > the port, where the scanner is connected to. > > > > I think you're right. But may be libusb is already updated in debian > > unstable. That would explain that my compilation works in ubuntu and > > library provided by ubuntu in libsane-extras package doesn't. So my > > conclusion would be the same. Backends need to be compiled against > > current version of libusb. > > Could you please check which version of the libusb you/they use?
Debian: libusb-0.1-4 0.1.12-6 libusb-dev 0.1.12-6 Ubuntu: libusb-0.1-4 0.1.12-2 libusb-dev 0.1.12-2 > > > One thing that could be observed: In all cases, scanimage works fine - > > > guess > > > this is because it never closes the port until the scan process is done. > > > > I'm confused. Why should exist any difference between scanimage and xsane > > when > > both frontends use the same SANE API to access usb scanners? > > Guess it's the workflow. When you call scanimage, then the scanner is openend, > detected, configured, scanning is done, closed. > XSane tries to open and detect, then closes a device. Then then scan is done > upon request. And I think after the first close, the device (or the port) will > be suspended. I've compiled SANE backends in ubuntu. Instead of installing all project I've just overwritten libsane-hp3900.la and libsane-hp3900.so.1.0.18 in /usr/lib/sane with the ones generated in this compilation and xsane works retrieving scanned image without problems. Jonathan Bravo Lopez
