Commen=
t # 8
on bug 10588=
0
from David Henningsson
Hi,
I'm getting the same or similar error:
* Black screen, no plymouth
* "Cannot find any crtc or sizes" error in dmesg
* amdgpu.dc=3D0 works around the issue
...and I might have a lead on it. The regression is between 4.15rc2 and 4.1=
5rc3
(found by downloading kernels from
http://kernel.ub=
untu.com/~kernel-ppa/mainline/).=20
The only one commit I could see being relevant between 4.15rc2 and 4.15rc3 =
is
this one:
commit a703c55004e1c5076d57e43771b3e11117796ea0
Author: Daniel Vetter <dan=
iel.vetter@ffwll.ch>
Date: Mon Dec 4 21:48:18 2017 +0100
drm: safely free connectors from connector_iter
...it seems relevant because the error I get is "Cannot find any crtc =
or
sizes", and the code emitting this error message (in
drivers/gpu/drm/drm_fb_helper.c) deals with connectors.
So could this commit cause connectors to be freed where the previous code d=
id
not? It seems like this could be the case, but only if (obj->free_cb =3D=
=3D NULL) -
drm_connector_put checks for a obj->free_cb being null whereas
drm_connector_put_safe decrements a refcount regardless of whether a free_c=
b is
present or not.
Does all this make sense, or am I out on deep water here?