[sane-devel] usb-IO-error with genesys

[svoltz@wanadoo.fr]

	Hello,

	the Canon lide 50 is reported to be a GL841 scanner, not a GL646. When 
I had a look at lide 80's log which were posted on the list, one difference I
could see was that th GL841 uses endpoint 0x83 for register bulk write, while
GL646 uses 0x82 (value = 130 below):

> [genesys] genesys_write_register (0x0e, 0x00) completed
> [genesys] genesys_bulk_write_register (size = 162)
> [sanei_usb] sanei_usb_control_msg: rtype = 0x40, req = 4, value = 130, 

	This explains the timout, since the backend is writing at the wrong
endpoint. Current genesys backend isn't suited for your scanner. 
	Before doing any developpment, I think we should compare GL646 and GL841
to see what are the differences, and if we can have support for both in one
backend, or two different backends possibly sharing a lib for things they have
in common.

Regards,
	Stef