Hello,
I can only communicate with a USB device using libusb when I'm logged in as root. I reported this previously for libusb-0.1.12, and have since tried upgrading to libusb-1.0 with the libusb-compat patch.
My system:
OpenSUSE 10.3, i386
communication is with a Tektronix TDS2014B oscilloscope using pyusb (a Python wrapper for libusb-0.1)
udev version 114-19
The problem is not present on an OpenSUSE 10.0 machine running identical code with straight libusb-0.1/pyusb
/etc/udev/rules.d/55-libsane.rules contains the following lines (among many others):
# ENV{DEVTYPE}=="usb_device", NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0664", OWNER="root", GROUP="root"
SUBSYSTEM=="usb", ACTION=="add|change", SYSFS{idVendor}=="0699", SYSFS{idProduct}=="0368", GROUP="usb", MODE="0664"
The 'scope's /dev/bus/usb/ entry looks like:
crw-rw-r-- 1 root usb 189, 132 2009-01-02 17:09 005
The non-root user who tried to use this scope is a member of these groups:
users dialout uucp video usb
Further notes:
1) Other USB devices which aren't being accessed via libusb are accessible to non-root users (e.g. printer, thumbdrive)
2) System seems to require an external hub between the scope and PC for reliable communication, but I _think_ that's a separate hardware issue since it's present on both machines.
3) The exact error message is "error sending control message: Operation not permitted"
4) I can get an (apparently valid) DeviceHandle, but both reset() and getString() calls fail - with permissions as the cited reason.
Any guidance you can provide on the likely source of the problem (or troubleshooting tricks) would be welcome.
Thanks
-Sarah
--
To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
