[sane-devel] HP 7450C libusb problems

[Henning Meier-Geinitz]

Hi,

On Sun, Jun 06, 2004 at 08:12:51PM +0200, insane@piments.com wrote:
> Yes this seems to be a pretty broad issue with sane/libusb and more recent  
> 2.6.x kernels
> 
> I am getting very similar behaviour from my canoscan FB636U on  
> Athlon-XP/Gentoo/2.6.6 kernel.

That scanner is listed as "untested" so you were lucky if it worked.

> [ebuild   R   ] media-gfx/xsane-0.93
> [ebuild   R   ] media-gfx/sane-backends-1.0.14-r2
> [ebuild   R   ] dev-libs/libusb-0.1.8

Some more data points: Linux 2.6.7rc2, ohci host controller, libusb 0.1.8

The following scanners do work without any trouble:

Mustek 1200 CU (mustek_usb)
Mustek BearPaw 1200 CU (gt68xx)
Mustek BearPaw 2400 CU Plus (gt68xx)
Plustek OpticPro U16B (gt68xx)
Plustek Opticpro UT16 (plustek)

> It was scanning briefly at one stage and I think I was running early 2.6  
> kernels at that time although I can not be precise.
> 
> I does not appear to be a problem in the kernel itself since vuescan works  
> perfectly on this system.

That may be a hint, but needn't as SANE may trigger a bug in the
kernel by accessing the scanner differently.

> If sane is going to continue to be an option it appears some dev work is  
> needed to resolve this issue.

First, we need to find out when this bug happens and in which part of
SANE or the kernel it is.

> Could someone remind me what the debug line is for this scanner so I can  
> get more detailed output.

export SANE_DEBUG_CANON630U=255

For USB debug messages try also:

export SANE_DEBUG_SANEI_USB=255

Bye,
  Henning