Created attachment 124526 [details]
Problem: Laptop panel turns off during boot, which makes the laptop unusable.
Expected Results: Laptop panel is ON when I boot without "nomodeset", and I can use graphical UI.
Ubuntu 16.04 (clean install) with the latest (v4.7-rc3) manually installed kernel.
X.Org X Server 1.18.3
HP ProBook 4535
[AMD/ATI] Sumo [Radeon HD 6380G]
[AMD/ATI] Seymour [Radeon HD 6400M/7400M Series] (rev ff)
I used "nomodeset" kernel parameter to install Ubuntu, because without it I face the same bug - Laptop panel turns off during boot. UI works with this kernel parameter but it's not usable as it's very slow(!!!). When "nomodeset" is removed the system boots but the screen turns off during the boot.
Guys from #radeon channel on "irc.freenode.net" said:
<chithead> radeon 0000:00:01.0 is the sumo2 and it locks up
<chithead> radeon 0000:01:00.0 is the caicos but there seems to be no problem with it
<airlied> the problem is the sumo crashing and failing to train displayport
<airlied> as it's the travis bridge it's trying to modeset which is the panel
<airlied> fixing the travis bridge is the first problem
Created attachment 124527 [details]
Created attachment 124528 [details]
It looks like a GPU hang. I think the displayport failure is just a side effect of that. Does it work if you disable acceleration in X? To disable acceleration, add an /etc/X11/xorg.conf file with the following content:
Option "NoAccel" "true"
Now it works, but I see the same slow UI performance as with "nomodeset". I definitely would like to have UI working faster.
Created attachment 124532 [details]
Created attachment 124533 [details]
Attached new logs from the system with /etc/xorg.conf as you suggested.
Will it be fixed? If it will, then when and how can I help?
Life sucks without hardware acceleration ... .