On Nov 14, 11:43pm, Michael Alexander Green wrote:
> Which scanner are you using? How did you setup your scanner for USB? Which
> config files did you change? What was the syntax you used? Thanks.
Trent Shipley was also interested in these details, asking me for my
"USB tail of woe." I had meant to reply sooner, but was busy at the
time...
I have an HP ScanJet 6250Cxi.
As mentioned in my previous mail, it was connected to my computer via
the SCSI interface. I was seeing SCSI timeouts which were preventing
the scanner from operating reliably, so I decided to give USB a try.
I still don't have an explanation for the SCSI timeouts.
It is my understanding that the kernel version that you are using
makes a big difference when attempting to use USB. I'm running
2.4.0-test10. When configuring this kernel, you need to enable
some of the USB options. I have the following enabled:
CONFIG_USB=m
CONFIG_USB_DEBUG=y
CONFIG_USB_DEVICEFS=y
CONFIG_USB_UHCI=m
CONFIG_USB_SCANNER=m
CONFIG_USB_PRINTER=m
CONFIG_USB_HID=m
CONFIG_USB_KBD=m
CONFIG_USB_MOUSE=m
I can probably do without the last four, but I enabled them so that I
could experiment a bit if I get any more USB devices.
I have the following lines for usb and my scanner in modules.conf:
alias usb-controller usb-uhci
post-install usb-uhci modprobe scanner
I'd really prefer not to have the last line. It is my understanding
that you can do without this line if you use "policy scripts" and
possibly a usb daemon. I need to do more investigation regarding
these facilities.
There is a directory /proc/bus/usb. This needs to be mounted in order
for you to be able to make use of the devices in /dev/usb. Either
do
mount -t usbdevfs usbdevfs /proc/bus/usb
or put the appropriate line in your /etc/fstab. RH7 runs this command
for you in rc.sysinit.
Finally, you'll need to change the configuration file that SANE
uses to find your scanner. I have the following two lines in
/etc/sane.d/hp.conf:
/dev/usb/scanner0
option connect-device
....
With regard to the tail of woe that Trent Shipley asked for, probably
the biggest problem I had was that I didn't power cycle my scanner
in between asking it to be a SCSI device and being a USB device. I
spent a lot of time fiddling with options, rebooting my system, etc.
when all I would've had to do would be to unplug the scanner, wait a
few seconds, and then plug it in again.
Another problem was that although I do have USB ports on my computer,
I didn't realize that I had to enable them in the BIOS.
I would estimate that 75% of the time that it took for me to set up
USB was "wasted" on these two problems.
....
The following URL is very helpful:
http://www.linux-usb.org/
I also read many of the files in Documentation/usb (in the kernel
sources). In particular, the file scanner-hp-sane.txt describes the
layout of the configuration lines in hp.conf. Also, proc_usb_info.txt
describes the USB filesystem mounted at /proc/bus/usb.
Kevin