On 27/05/2013 15:49, Tom Pace wrote:
> On 05/27/2013 04:59 AM, Mike Cloaked wrote:
>> On Mon, May 27, 2013 at 12:10 AM, Tom Pace <tompace101 at gmail.com
>> <mailto:tompace101 at gmail.com>> wrote:
>>
>> I couldn't find any information about USB 3 and SANE, but on my
>> particular hardware it doesn't seem to be supported. My Epson
>> Perfection
>> V33 works fine when plugged into a USB 2 port, but when plugged
>> into a
>> USB 3 port it rarely works. I'm using the epkowa backend, and have
>> attached a log.
>> For all I know it could be the scanner itself doesn't support USB 3.
>> Even though USB 3 is supposed to be backwards compatible, I
>> understand
>> it doesn't always work as advertised.
>>
>> Thanks for any insight,
>>
>>
>> Just for clarification does the scanner work when plugged into a usb2
>> port on the "same" machine that it doesn't work when plugged into a
>> usb3 port?
>>
>> I have a different scanner (MFP) which was plugged into a usb3 port
>> and didn't work, but which worked when plugged into a different
>> machine that only had usb2 - but I was chasing the wrong problem
>> because it was the same non-functional state when plugged into a usb2
>> port on the original machine - and it turned out that the problem was
>> with udev not knowing how to have both a printer and scanner function
>> on the MFP working at the same time.
>>
>> However I would also like to know more about whether usb3 is fully
>> supported (both for any scanner that does have usb3 but also for
>> backwards compatibility with usb2 on a computer that does not support
>> usb3.
>> --
>> mike c
>
> Yes, it is the same machine. It is a laptop running Linux Mint 13.
> There are 2 USB3 ports that the scanner doesn't work very well on, and
> 1 USB2 port that it works perfectly on. The specs on the scanner
> itself do not mention USB3, so it seems that the backwards
> compatibility is failing somewhere. It could be within SANE, or it
> could be within the scanner itself, or I suppose it could even be some
> other driver/hardware on the laptop. Does anyone have any ideas how I
> could go about narrowing this down?
>
> Thanks,
> Tom
>
>
>
Hello,
I don't know if it is the problem you have, but I have recently met
some troubles using USB scanners on recent hardware with USB3. I
eventually cured it by disabling USB powersaving with this kernel module
option:
modprobe usbcore autosuspend=-1
or if usbcore is not a module with this kernel boot parameter:
usbcore.autosuspend=-1
Regarding USB3/USB3 the last paragraph of
/usr/src/linux/Documentation/usb/power-management.txt might be interesting.
Regards,
Stef
