[sane-devel] Can't download firmware to my scanner

[billy2000@fastmail.fm]

Hi, 

I have been having trouble getting my Epson 1670 scanner working
properly. Oliver was helping me and we made some progress but he has
suggested I come back to the list now to see if anyone here has
experience with USB 2.0.

The scanner works when I attach it to a USB 1.1 port, or if I unload the
ehci_hcd driver (rmmod ehci_hcd), it works on the USB 2.0 port, but only
as a USB 1.1 device.

When I try to use it on the USB 2.0 port with the ehci_hcd driver
loaded, it seems to work as first; it is visible to scanimage -L:

# scanimage -L
device `v4l:/dev/video0' is a Noname Vanilla iTVC15 card virtual device
device `snapscan:libusb:004:002' is a EPSON EPSON Scanner flatbed
scanner
#

...but when I try to access the scanner in any way (e.g. using xsane,
kooka, or scanimage -T -d snapscan:libusb:004:002), it fails and the usb
driver seems to crash, so the device is no longer visible to scanimage-L
until everything has been reset.

I sent Oliver the SANE_DEBUG_SANEI_USB=255 dump, and he said it looked
like a problem with either libusb or the kernel driver, and that I
should come back to the sane-devel list to see if anyone has experience
or ideas about this mater.  Please let me know if you have any ideas.

- Joe



On Fri, 3 Jun 2005 18:09:18 +0200, "Oliver Schwartz"
<Oliver.Schwartz@gmx.de> said:
> Hi Joe,
> 
> > I actually have two usb cards in my computer, one is USB 1.1, the
> > other (which I have been using for the scanner) is USB 2.0.
> >
> > Based on your suspiscion of the USB layer, I tried attaching the
> > scanner to a USB 1.1 port... and it worked! So it is indeed a USB
> > problem of some sort.
> >
> > Obviously, I want to get the scanner working on USB 2.0... so I
> > have attached the logs as you requested below. The logs have the
> > output of the following commands:
> >
> > scanimage -L
> > scanimage -T -d snapscan:libusb:006:002 -v -v
> > lsusb -v
> >
> > Thanks for any advice you can provide. I am not sending this
> > message to the list because the error output is so huge.
> 
> That's very interesting. I've long suspected that there might be 
> something strange going on with USB 2.0 hardware, but I've never been 
> able to verify it.
> 
> Unfortunately the log doesn't help much - the sanei_usb layer receives 
> the complete dataset but only sends out 1024 bytes. The problem seems 
> to be located either in libusb or the kernel driver.
> 
> I'm no expert on the low level stuff, so I don't think I can 
> contribute a lot (besides, I'm leaving for a one week holiday 
> tomorrow). One test you should try is unloading the ehci_hcd driver 
> and see if you still can use the scanner on the USB 2.0 port (it 
> should use the ohci_hcd driver in this case).
> 
> Please post your findings to sane-devel as well (without the dump), 
> maybe somebody else out there has some experience on the matter.
> 


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