7

When I try to start my WM using startx, I am unable to because the permission of something called /dev/fb0 are restricted.

From home/user/.local/share/xorg/Xorg.0.log:

[   198.569] (--) controlling tty is VT number 1, auto-enabling KeepTty
[   198.569] (II) Loading sub module "fbdevhw"
[   198.569] (II) LoadModule: "fbdevhw"
[   198.569] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[   198.570] (II) Module fbdevhw: vendor="X.Org Foundation"
[   198.570]    compiled for 1.16.0, module version = 0.0.2
[   198.570]    ABI class: X.Org Video Driver, version 18.0
[   198.570] (EE) open /dev/fb0: Permission denied
[   198.570] (WW) Falling back to old probe method for fbdev
[   198.570] (II) Loading sub module "fbdevhw"
[   198.570] (II) LoadModule: "fbdevhw"
[   198.570] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[   198.570] (II) Module fbdevhw: vendor="X.Org Foundation"
[   198.570]    compiled for 1.16.0, module version = 0.0.2
[   198.570]    ABI class: X.Org Video Driver, version 18.0
[   198.571] (EE) open /dev/fb0: Permission denied

Now of course I can change it using chmod, but I shouldn't have to do that every time I reboot the computer, so it seems like something is wrong / I haven't set up something properly.

What should I do to fix this?

  • 4
    It's a consequence of the recent change to rootless X (i.e. the X server doesn't run as root any longer). Looks like rootless X is not ready for prime time on Arch. You can arrange to get the permission to access /dev/fb0, but you should not have to (if you google, you'll find recommendations to add yourself to the video group… but that's propping the armored door open, it defeats the purpose). – Gilles 'SO- stop being evil' Aug 13 '14 at 0:30
11

Gilles is correct; this is due to the changes in xorg-server 1.16 which were announced on the Arch News.

To work around the permissions issue, you can use a Xorg.wrap config file to pass root rights, using:

needs_root_rights = yes

See man Xorg.wrap for the details.

You could also try using xf86-video-modesetting instead of xf86-video-fbdev until the fbdev driver is updated.

  • 3
    I have this same problem with Fedora but this solution doesn't help I have /etc/X11/Xwrapper.config with allowed_users=anybody and needs_root_rights=yes. Any suggestions? – Magpie Jun 28 '15 at 11:18
  • I second @Magpie's comment, even though (not sure whether it matters) inserting a space before and after the "=" sign for each key-value pair in Xwrapper.config might help. In my case, having needs_root_rights = yes generates a few other errors, which weren't there to begin with, i.e. when only (EE) open /dev/fb0: Permission denied showed. – Cbhihe Sep 30 '18 at 11:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.