[sane-devel] CanoScan LiDE30 problem

[Gerhard Jaeger]

On Thursday 06 December 2007 09:18:36 Johannes Ranke wrote:
> Hi Gerhard and Gerard,
> (replying to Gerard because I didn't receive Gerhards mail since I am
> not on the list)
> 
> Thanks for the suggestion with CONFIG_USB_SUSPEND! I just booted a
> self-compiled kernel without this option, and scanning works again from
> the graphical frontends. What I don't understand is why it works from
> the command line with scanimage, but not with the graphical frontends.
> 

The GUI frontends are checking for the device and the release it.
This is the point, where the USB subsystem waits some time and decides
to go to the suspend mode - which the scanners don't like.

scanimage itself, opens the device and scans without giving the USB
subsystem the chance to go to sleep...

AFAIK, there's a workaround in more recent kernels, but I don't
recall - maybe Julien?

Another workaround came to my mind: use the scanbutton daemon,
which checks each 200ms for a pressed scanner button. That way,
the USB won't also fell asleep...

Ciao,
Gerhard