I have just committed an attempted workaround for this Linux kernel bug. I have tested with Fujitsu and Canon scanners, and it does fix the problem. I have not tested with other scanners. We need as much testing on this as we can get. Please build from a current git checkout (or tomorrow's git snapshot), and let us know what you find.
allan On Thu, Dec 11, 2014 at 9:05 PM, m. allan noah <[email protected]> wrote: > On Thu, Dec 11, 2014 at 2:21 AM, Olaf Meeuwissen > <[email protected]> wrote: >> >> m. allan noah writes: >> >>> I have just pushed your patches to git. They don't seem to help with >>> any scanner that I have, but I doubt they will hurt anything. >> >> Thanks! >> >>> It appears that we also have USB3 issues with Canon scanners as well- >>> they do use clear_halt frequently, and it seems that maybe the Linux >>> kernel is not passing them down to the scanner in some cases. >> >> Do they halt/stall that frequently? If there's no stall, clear_halt >> should not be used, IIUC. Hmm, it doesn't look like sanei_usb allows >> you to find out about that ... > > Yeah, the Canon machines halt at the drop of a hat. I added > sanei_usb_clear_halt specifically for them. > > But, no matter. Based on the threads linked from this post: > http://www.spinics.net/lists/linux-usb/msg105515.html I have come up > with a workaround that fixes both the Canon and the Fujitsu machines I > have access to. It seems the xhci controller refuses to transmit a > clear_halt to the device or reset the data 0/1 toggle in the host when > the ehci controller would. However, sending a set_interface command > for the interface that is already selected, seems to do both of those > things. So, I added a call to > > sanei_usb_set_altinterface (s->fd, 0); > > right before the calls to sanei_usb_close() or sanei_usb_clear_halt() > in those two backends, and everything suddenly seems to work. > > I need to do some further testing, and see if these changes should be > moved up to sanei_usb instead of the backends. > > allan > -- > "well, I stand up next to a mountain- and I chop it down with the edge > of my hand" -- "well, I stand up next to a mountain- and I chop it down with the edge of my hand" -- sane-devel mailing list: [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel Unsubscribe: Send mail with subject "unsubscribe your_password" to [email protected]
