[sane-devel] Is the Iscan backend "epkowa" also affected by USB3 issues?
olaf.meeuwissen at avasys.jp
Wed Apr 27 23:45:48 UTC 2016
I'll forward your question as I am no longer doing any scanner work at
the office (as of the end of March 2016). As we are just one day away
from Golden Week, it will probably take a while before you get an
answer (if at all). I think people will only get back to the office
OK, now on to your question,
Johannes Meixner writes:
> Now I wonder if the "epkowa" backend could be also affected by the
> current sane-backends 1.0.25 "Workaround for USB3 problems in Linux
> kernel" that seems to no longer work with newest kernels, cf.
> In other words, I wonder if the "epkowa" backend uses the
> sane-backends USB code or if the "epkowa" backend implements USB
> communication on its own.
The epkowa backend uses its own *copy* of the sanei_usb code. There was
a minor fix for USB 3.0 connected scanners in 2.30.1 (dated 2014-12-03).
That same fix was applied to sane-backends on 2014-12-10.
Please note that iscan does *not* actively track changes to the
sane-backends version of the sanei_usb code. Also, iscan-2.30.1 is the
most recent version.
> In the end I like to understand if a version change of the installed
> sane-backends software on the user's computer could make a difference
> whether or not the "epkowa" backend works with the xhci_hcd kernel
That is rather unlikely but not impossible as it may depend on what
other backends do during their sane_init() and sane_get_devices(). If
all other backends are disabled, changing the version of the installed
sane-backends should not make a difference. That is because the dll
backend doesn't do anything USB related itself.
Hope this helps,
Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- EPSON AVASYS CORPORATION
Free Software Foundation Associate Member since 2004-01-27
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