Re: [avrdude-dev] USB

[Russell Shaw]

Joerg Wunsch wrote:
> As Russell Shaw wrote:
>
> > I just got a usb AVRISP. What permission should i fix?
>
> You need read/write permission.
>
> As these devices are created dynamically, you cannot do that with a
> plain chmod, but you have to consult your systems dynamic device
> facilitie's documentation.  Most Linux systems use udev for that
> purpose, so you'd have to add another udev rule for the VID/PID pairs
> you are interested in.

Hi,
Avrdude runs ok as root, but not as a normal user.

I traced in to libusb:

(gdb) bt
#0  usb_control_msg (dev=0x82437a8, requesttype=128, request=6, value=768, 
index=0, bytes=0xbfffd245 "\333", <incomplete sequence \373\267>, size=255, 
timeout=1000) at ../linux.c:143

#1  0xb7fbeaea in usb_get_string (dev=0x82437a8, index=0, langid=0, 
buf=0xbfffd245 "\333", <incomplete sequence \373\267>, buflen=255) at ../usb.c:226

#2  0xb7fbeb32 in usb_get_string_simple (dev=0x82437a8, index=3, buf=0xbfffd484 
"\1", buflen=256) at ../usb.c:242

#3  0x08073d1d in usbdev_open (port=0xbffff985 "usb", baud=8452, fd=0x8099528) 
at usb_libusb.c:117

#4  0x0806d95a in stk500v2_open (pgm=0x8098468, port=0xbffff985 "usb") at 
stk500v2.c:1271

#5  0x0804b239 in main (argc=9, argv=0xbffff7c4) at main.c:778


usb.c:242

char tbuf[255];       /* Some devices choke on size > 255 */
...
ret = usb_get_string(dev, 0, 0, tbuf, sizeof(tbuf));


This returns -1 and i can't figure out why. The system hasn't
read anything out of /dev yet.

Just to make sure of things, i also tried:

# chown -R root:avrdude /dev/usb*
# chown -R root:avrdude /dev/bus/usb
# chmod -R 660 /dev/usb*
# chmod -R 660 /dev/bus/usb

and i'm in group avrdude. I have the avrisp plugged in.