[radeon] sumo2 locks up and fails to train displayport during boot (panel turns off)
Submitted by Kostiantyn P
Assigned to xf86-video-ati maintainers
Description
Created attachment 124526
dmesg output
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.
Environment:
Ubuntu 16.04 (clean install) with the latest (v4.7-rc3) manually installed kernel.
X.Org X Server 1.18.3
Hardware:
HP ProBook 4535
[AMD/ATI] Sumo [Radeon HD 6380G]
[AMD/ATI] Seymour [Radeon HD 6400M/7400M Series] (rev ff)
Overview:
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
Attachment 124526, "dmesg output":
dmesg.out