user lacks permissions for /dev/dri/card0

RandomTroll · 05-20-2020, 01:33 PM

Beginning today /dev/dri/card0 lacks permissions for users: user can't view an image. What sets the permissions of this file? What creates it? I can add setting them to rc.local, so the problem is easy to solve. I want to know why it's happening.

teckk · 05-20-2020, 03:46 PM

Root should own it.

Code:

ls -l /dev/dri/card0
crw-rw----+ 1 root video 226, 0 May 13 16:29 /dev/dri/card0

file -s /dev/dri/card0
/dev/dri/card0: ERROR: cannot read `/dev/dri/card0' (Resource temporarily unavailable)

The 226, 0 tells that major number is 226 and the minor is 0. c for character device.

Look in /sys/dev

Code:

/sys/dev/char/226:0

readlink /sys/dev/char/226\:0/device/driver
../../../bus/pci/drivers/nouveau

Edit:
This too

Code:

udevadm info -a -n /dev/dri/card0

RandomTroll · 05-22-2020, 10:31 PM

I view images with fbi. It stopped working, complaining that it couldn't access /dev/dri/card0. I changed that file's permissions to 666, now it works. I've been viewing images with fbi for years. Something changed to make it stop working. What?

I have the same problem with fbpdf; changing the permissions of /dev/fb0 to 666 made it work.

Something happened, perhaps in a kernel update (I build them, use latest.)