[SRU][Artful][PATCH 0/1] drm/i915/fbdev: Always forward hotplug events

Joseph Salisbury joseph.salisbury at canonical.com
Wed Dec 6 19:27:21 UTC 2017

BugLink: http://bugs.launchpad.net/bugs/1724911

== SRU Justification ==
The bug reporter states that after upgrading his laptop to Ubuntu 17.10, he was
unable to access gettys on any of the text-mode VTs on his system.

gdm3 is running on VT1, his user session is running on VT2. He could switch 
between these. If he switched to VT3, the display retained the output of 
his X session, and the text console with getty never appears.  Switching 
back to VT2 works fine.

The same problem was occuring with either Wayland or X.

This bug is a regression in Artful introduced by mainline commit:
7581d5ca2bb ("drm/i915/fbdev: Check for existence of ifbdev->vma before operations").

It was first found that this bug was fixed in v4.14-rc1.  However, after a lengthy
"Reverse" bisect, the exact commit could not be identified.  This is because the 
fix came in via a merge base.  A regular bisect was then done to identify commit
7581d5ca2bb as the offending commit that introduced the bug.  Using the file 
that this commit touched, a "Reverse" bisect was done again between 
7581d5ca2bb..v4.14-rc1.  This identified the following commit 88be58be886f as 
the fix to this regression.

== Fix ==
commit 88be58be886f1215cc73dc8c273c985eecd7385c
Author: Daniel Vetter <daniel.vetter at ffwll.ch>
Date:   Thu Jul 6 15:00:19 2017 +0200

    drm/i915/fbdev: Always forward hotplug events

== Regression Potential ==
This patch fixes a current regression and is a minor one-liner.

== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.

Daniel Vetter (1):
  drm/i915/fbdev: Always forward hotplug events

 drivers/gpu/drm/i915/intel_fbdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


More information about the kernel-team mailing list