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. 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.
allan On Wed, Dec 10, 2014 at 6:55 PM, Olaf Meeuwissen <olaf.meeuwis...@avasys.jp> wrote: > Hi Allan, > > m. allan noah writes: > >> Your patch makes no difference for the Fujitsu models in question. >> I'll commit the patch in the next couple days, after some more >> testing. > > Any progress on this? > >> allan >> >> On Mon, Dec 1, 2014 at 9:44 PM, m. allan noah <kitno...@gmail.com> wrote: >>> Ha! As we speak, I am digging into USB3 again, because command >>> counting seems to not fix every case. I will try your patch and report >>> back. >>> >>> allan >>> >>> On Mon, Dec 1, 2014 at 9:21 PM, Olaf Meeuwissen >>> <olaf.meeuwis...@avasys.jp> wrote: >>>> Olaf Meeuwissen writes: >>>> >>>>> m. allan noah writes: >>>>> >>>>>> I have added a USB3 port to my computer, and have spent a few days >>>>>> investigating this problem. >>>>> >>>>> I haven't had that kind of time, yet :-( >>>> >>>> Finally got time to do so. >>>> # Someone managed to sky-rocket the priority of USB3 support to the top >>>> # of my TODO list ;-) >>>> >>>>>> It seems to be a bug in Linux kernel related to a bookkeeping error >>>>>> when the USB device is closed. [...] >>>> >>>> Based on two days of looking at USB3 behaviour with three EPSON scanners >>>> and three backends, that does not seem to be the whole story. >>>> >>>>>> I have committed these changes to sane-backends git repo in >>>>>> 7a590f362e7e93979b706dd9e6ae34584e926ec3. If users of fujitsu scanners >>>>>> could try it out, I would appreciate any feedback. Note that this does >>>>>> not fix USB3 problems in other sane backends. Until the kernel is >>>>>> fixed, these types of repairs will have to be made on a per-backend >>>>>> basis, at the discretion of the maintainer. >>>> >>>> The epson and epson2 backends have been and still are using the kind of >>>> command counting and making sure to send an even count of reads and >>>> writes you added to the fujitsu backend. That notwithstanding, they >>>> suffer from USB3 I/O problems with the Perfection V700 (GT-X900) and >>>> ES-H300 (GT-2500). The epkowa backend does *not* even up the reads and >>>> writes and unsurprisingly shows the same problems. In addition, the >>>> GT-D1000 (GT-1500), a non-free plugin needing device, is also affected. >>>> >>>> Making the epkowa backend even up the reads and writes did *not* fix the >>>> problem. What did fix the problem for all three scanners and all three >>>> backends for me was a tiny change in sanei_usb.c. With that change, the >>>> evening up of reads and writes was not needed either. >>>> >>>> The sanei_usb.c code unconditionally sets the USB configuration. This >>>> happens even if the device has only one. I found that *not* setting the >>>> USB configuration when there is only one fixed all my USB3 problems. My >>>> understanding of the USB2 and USB3 standards is that the default USB >>>> configuration has to be set before devices become available to libusb. >>>> If that understanding is correct, then there is no need to set it unless >>>> you need a configuration that *differs* from the current one. With only >>>> one configuration to choose from, there is then no need to set it. >>>> >>>> This patch does exactly that. It skips setting the USB configuration if >>>> there is only one. It should not break USB for any of the backends and >>>> *may* fix USB3 for all of them. >>>> >>>> Note: it may still set the default configuration if there are multiple >>>> ones to choose from. I have no devices I can test with to see if >>>> that is problematic or not. Even so, modifying the code to only >>>> set a USB configuration if it differs should be safe. >>>> # Patch is in preparation. >>>> >>>> Allan, can you locally revert your fujitsu fixes and try with the patch >>>> I applied? Does that fix your USB3 issues? Do you still need to even >>>> up the reads and writes? >>>> >>>> Unless it breaks things for you, could you please commit my patch? >>>> # Even if it does not fix USB3 for you. >>>> >>>> Other people with USB3 issues are of course more than welcome to try >>>> this patch too! >>>> >>>>> [...] > > Hope this helps, > -- > Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- AVASYS CORPORATION > FSF Associate Member #1962 Help support software freedom > http://www.fsf.org/jf?referrer=1962 -- "well, I stand up next to a mountain- and I chop it down with the edge of my hand" -- sane-devel mailing list: sane-devel@lists.alioth.debian.org http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel Unsubscribe: Send mail with subject "unsubscribe your_password" to sane-devel-requ...@lists.alioth.debian.org