If other processes have had drm open previously, xserver may attempt to
open the device too early and fail, with xserver error exit "Cannot
run in framebuffer mode" or Xorg.0.log messages about "setversion 1.4
failed".
In this situation, we're receiving back -EACCES from libdrm. To address
this we need to re-set ourselves as the drm master, and keep trying to
set the interface until it works (or until we give up).
See https://bugs.launchpad.net/ubuntu/+source/libdrm/+bug/982889
Signed-off-by: Bryce Harrington <bryce@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
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