[sane-devel] Scanner (USB) not found after kernel upgrade

[Till Kamppeter]

Johannes Meixner wrote:
> Hello,
> 
> On Feb 7 21:32 Till Kamppeter wrote (shortened):
> 
>>The usblp module can be replaced by a libusb-based CUPS backend.
>>Download
>>
>>http://www.linuxprinting.org/till/tmp/usb-libusb.c
>>
> 
> ...
> 
>>The libusb-based CUPS backend is written by Couriousous, a Mandriva
>>contributor, thanks to him for this work. I CC him, so that he can
>>perhaps help on this issue.
> 
> 
> I do not understand how the original code should work
> (at least not for CUPS 1.1.x) because there is no "main" function.
> Doesn't each CUPS backend run as stand-alone program?
> 

Sorry, forgot to give the correct instructions. Here are the
instructions which Couriousous has given:

I've written a cups libusb backend. It is "source-compatible" with
usb-unix.c. To use it, edit usb.c and change the usb-unix.c include by
usb-libusb.c. Then compile with -lusb ( by setting LDFLAGS ). It's based
on usb-unix.c, highly inspired of usblp kernel module and sane.

> 
> 
>>Another problem is the memory card reader in the Epson photo printers
>>and MF devices, AFAIK there is no libusb-based driver for USB mass
>>storage devices, and no solution to provide mountable file systems
>>completely in user space.
> 
> 
> Yes.
> 
> For me it hangs up during list_devices() with endless
> ---------------------------------------------------------
> INFO: USB printer is busy; will retry in 5 seconds...
> ---------------------------------------------------------
> messages and dmesg reports
> ----------------------------------------------------------------
> usbfs: interface 2 claimed by usb-storage while ... sets config
> ----------------------------------------------------------------
> I don't know if it is possible with libusb but it should
> give up after a short time instead of endless probing
> (perhaps one can replace the unlimited "while" loops
> with limited "for" loops).
> 
> After
> rmmod usb-storage
> it detects my EPSON Stylus Photo RX420 correctly.
>     
> The conflict with usb-storage is because the RX420 has also
> a cardreader unit included.
>

And on which level this has to be fixed? Here only CUPS and the kernel
are involved. But here there is still a bug, printer/card reader combos
from Epson worked for a long time, until the most recent kernel changes
were done.

   Till