[sane-devel] Permission denied on parallel port Epson Expression636

[Petr Hlustik]

Hello,

I got my hands on the Epson Expression636 which comes with both SCSI and
parallel ports. W/o SCSI on my RedHat8 box, I tried the parallel
port. Scanning works if I'm root (Yes!!) but not as a regular user. This my
diagnostics:

SANE_DEBUG_EPSON=9 scanimage -d epson:0x378 > pnm.out

[sanei_debug] Setting debug level of epson to 9.
[epson] sane_init: sane-backends 1.0.8
[epson] sane_init, ># epson.conf<
[epson] sane_init, >#<
[epson] sane_init, ># here are some examples for how to configure the EPSON backend<
[epson] sane_init, >#<
[epson] sane_init, ># SCSI scanner:<
[epson] sane_init, >#scsi EPSON<
[epson] sane_init, >#<
[epson] sane_init, ># Parallel port scanner:<
[epson] sane_init, >#pio 0x278<
[epson] sane_init, >pio 0x378<
[epson] sane_init, >pio 0x378<
[epson] attach(pio 0x378)
[epson] SANE Epson Backend v0.2.21 - 2002-04-22
[epson] attach(pio 0x378)
[epson] attach: opening pio 0x378
[epson] dev_open: Invalid argument: can't open 0x378 as a parallel-port device
[epson] sane_init, >#pio 0x3BC<
[epson] sane_init, >#<
[epson] sane_init, ># USB scanner - only enable this if you have an EPSON scanner. It could<
[epson] sane_init, >#               otherwise block your non-EPSON scanner from being<
[epson] sane_init, >#               recognized.<
[epson] sane_init, >#           Depending on your distribution, you may need either the<
[epson] sane_init, >#           first or the second entry.<
[epson] sane_init, >#usb /dev/usb/scanner0<
[epson] sane_init, >#usb /dev/usb/scanner0<
[epson] sane_open(0x378)
[epson] SANE Epson Backend v0.2.21 - 2002-04-22
[epson] attach(0x378)
[epson] attach: opening 0x378
[epson] dev_open: Error during device I/O: can't open 0x378 as a parallel-port device
scanimage: open of device epson:0x378 failed: Error during device I/O

Seeing that /dev/lp0 has rw access by root.lp, I added myself to the lp
group to no effect. I suspect the Epson backend is using some direct write
to the binary address bypassing /dev/lp0.

Searching the archive and Google yielded nothing.

Thanks for your help.

Best,
Petr