Lenovo ThinkPad E455 (Kaveri A10-7300): Blank built-in screen with radeon kms driver
Submitted by Samir Ibradžić
Assigned to Default DRI bug account
Description
Created attachment 115550
dmesg 4.1 rc1
As soon as the radeon kms switches in from efifb, the screen goes blank for the moment (no backlight), and then the backlight switches in, but the screen remains black. External HDMI output works just fine. No X is involved, I can't even see the kms console @ eDP. I can even control the backlight on the eDP display, but all i get is the various shades of black. Fglrx works fine, although it flickers wildly before the picture gets stable.
I've tried numerous things, like forcing EDID that was grabbed from fglrx, disabling audio, applying all the DP training / backlight disabling patches as in https://bugs.freedesktop.org/show_bug.cgi?id=73530, all to no avail. Currently on linux 4.1rc1, tried 3.13, 3.16 & 3.19 as well, same issue.
Please help! I bought this laptop cause I prefer AMD, and was expecting Lenovo to work great with Linux, but so far its broken. Ready to try some patches...
Attachment 115550, "dmesg 4.1 rc1":
file_90320.txt