On Mon, 29 Jul 2019 10:16:00 +0100 Patrick Welche <pr...@cam.ac.uk> wrote:
> With biosboot set on the root partition of a GPT disk, I can now > biosboot or EFI boot the same computer. > > Thanks to mlelstv@'s hint, I can get a serial console on the EFI side > with consdev com,0x3f8,115200 > as well as the biosbooting side. > > In both cases, booting with the serial console, X works on this > nouveau GeForce GTX 680. > > However, if I boot without the serial console. I see nothing on > screen in the EFI case, but all is OK in the biosboot case. (Unsure: > typing blindly I did not get X to start in the EFI case, but fat > fingering possible.) > Hi, I see about the same behavior with a GT710 booted with efi, either the machine stops the moment the frame buffer should get activated or the screen is all black afterwards with the machine running otherwise. The last lines displayed are: nouveau0: error: priv: HUB0: 086014 ffffffff (1a70828c) nouveau0: info: fb 2048 MiB GDDR5 The Situation with a radeon card (either R5 230 or R7 240) is like it but not entirely. With bios boot both cards initialize properly during drmkms startup. With efi boot both hang about 11sec during initialization with the following messages: *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, giving up!!! failed initializing UVD (-1). the code printing the error messages has some delays and retries that add up to the delay... but the framebuffer comes to live afterwards. In case of the R7 240 no glamor acceleration but that's a different story. I'm not very deep into the drm code but my guess is, something is missing about taking over/releasing the efi console and thats blocking proper initialization as said just a guess. Lars ----- You will continue to suffer if you have an emotional reaction to everything that is said to you. True power is sitting back and observing everything with logic. If words control you that means everyone else can control you. Breathe and allow things to pass. --- Bruce Lee
