[sane-devel] canon dr-2580c invalid argument

[gobo]

i'm trying to deploy a canon dr-2580c.  edited the dll.conf file and
the scanner is detected.

scanimage -L
device `canon_dr:libusb:001:008' is a CANON DR-2580C scanner

but when i try to use it, i get the infamous Invalid argument.

scanimage -d canon_dr:libusb:001:008 -v > tt.pnm
scanimage: sane_start: Invalid argument


debug:

scanimage -d canon_dr:libusb:001:008 -v
[sanei_debug] Setting debug level of dll to 4.
[dll] sane_init: SANE dll backend version 1.0.12 from sane-backends1.0.20
[dll] sane_init/read_dlld: opendir failed: No such file or directory
[dll] add_backend: adding backend `canon_dr'
[dll] sane_open: trying to open `canon_dr:libusb:001:008'
[dll] load: searching backend `canon_dr' in `/usr/lib64/sane'
[dll] load: trying to load `/usr/lib64/sane/libsane-canon_dr.so.1'
[dll] load: dlopen()ing `/usr/lib64/sane/libsane-canon_dr.so.1'
[dll] init: initializing backend `canon_dr'
[dll] init: backend `canon_dr' is version 1.0.26
[dll] sane_open: open successful
[dll] sane_get_option_descriptor(handle=0x60db00,option=0)
[dll] sane_control_option(handle=0x60db00,option=0,action=0,value=0x7fffae2a64e8,info=(nil))
[dll] sane_get_option_descriptor(handle=0x60db00,option=0)
[dll] sane_control_option(handle=0x60db00,option=0,action=0,value=0x7fffae2a63d4,info=(nil))
[dll] sane_get_option_descriptor(handle=0x60db00,option=1)
[dll] sane_get_option_descriptor(handle=0x60db00,option=2)

~~stuff deleted

[dll] sane_get_option_descriptor(handle=0x60db00,option=34)
[dll] sane_control_option(handle=0x60db00,option=9,action=0,value=0x60b690,
info=(nil))
[dll] sane_control_option(handle=0x60db00,option=7,action=0,value=0x7fffae2a63d0,info=(nil))
[dll] sane_control_option(handle=0x60db00,option=10,action=0,value=0x60b694,
info=(nil))
[dll] sane_control_option(handle=0x60db00,option=8,action=0,value=0x7fffae2a63d0,info=(nil))
[dll] sane_control_option(handle=0x60db00,option=7,action=0,value=0x7fffae2a64e0,info=(nil))
[dll] sane_get_option_descriptor(handle=0x60db00,option=9)
[dll]sane_control_option(handle=0x60db00,option=9,action=1,value=0x7fffae2a64dc,info=0x7fffae2a63dc)
[dll] sane_control_option(handle=0x60db00,option=8,action=0,value=0x7fffae2a64e0,info=(nil))
[dll] sane_get_option_descriptor(handle=0x60db00,option=10)
[dll] sane_control_option(handle=0x60db00,option=10,action=1,value=0x7fffae2a64dc,info=0x7fffae2a63dc)
[dll] sane_start(handle=0x60db00)
scanimage: sane_start: Invalid argument
[dll] sane_cancel(handle=0x60db00)
[dll] sane_close(handle=0x60db00)
[dll] sane_exit: exiting
[dll] sane_exit: calling backend `canon_dr's exit function
[dll] sane_exit: finished

i ran this with the usb debug enabled, got tons of output, but it does
open the device.

[sanei_usb] sanei_usb_open: opened usb device `libusb:001:008' (*dn=0)

the result is the same run when run as root.

i'm out of ideas.  does anyone have a suggestion?