In kernels >= 3.17, my AMD GPU does not seem to initialize. For full background (including lspci output, dmesg, symptoms, acpidump, bisection, and other pertinent info), please see bug #84221 Specifically, in addition to the attachments and description, see comment 23, 24, 25.
Please attach your full dmesg output (I couldn't find it on the other bug report). Note that the AMD card is not connected to the laptop panel. The AMD card is purely for offload rendering (e.g., AMD card renders a game and then the frame is sent to the Intel card for display).
Created attachment 154051 [details] dmesg output on 3.16.4-1
Dmesg output attached. The panel isn't attached to the AMD card? The ACPI issues in the other bug seem related to AMD, and it affects the display, even in TTY, so I had thought otherwise. Let me know if you need any other output
The radeon driver has initialized fine. There are no displays wired to the radeon card at all. It's purely for rendering offload. If you are not getting a display it's an issue with the intel driver.
(moved to Intel side)
We seem to have neglected this bug a bit, apologies. Is this still an issue with recent kernels? Please attach dmesg with drm.debug=14 module parameter set. Thanks.
Actually, my apologies- I think this can be closed. it seemed to be related to bug #84221 (which was then tracked in bug #84561). that's been fixed and incorporated into commit 7d0b93499f4879ddbc75d594f4ea216ba964f78e that hasn't hit mainline as of 3.18.2 but it does seem to be in mainline stable: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7d0b93499f4879ddbc75d594f4ea216ba964f78e (unfortunately i'm on a low-bandwidth connection so i can't clone the repo and see which tag it's under, and i'm not sure how to do that with cgit...) BUT the display is working properly with that commit. I think it's solving this bug as well, but can't check at the moment. I'll test later tonight and let you know!
Thanks, I'll close the bug - please reopen if the bug is still present.