Created attachment 125292 [details] full dmesg when experiencing the bug, and with drm.debug=14 log_buf_len=16M Hello, Since i upgraded my kernel from 4.5.4 to 4.6.3, the screen goes "blank" when entering KMS, instead of giving the high resolution tty. By "blank", i mean it has a uniform colour : during some boots it's pure red, other boots it's pure magenta, and sometimes pure white. The system is functional and i am able to ssh remotely into the machine. My setup : - single 2560x1440 monitor - NVIDIA Corporation GM204 [GeForce GTX 970] (rev a1) (prog-if 00 [VGA controller]) - both DVI and DisplayPort ports exhibit the issue - Arch Linux If i disable modesetting, i am able to see an image on the screen (low resolution tty) and login to the system (no Xorg though, as expected). I found bug 94990 which seems similar, although the symptoms are a bit different (his monitor goes to sleep, mine remains ON and monochromatic). Also, i have a similar motherboard (Z97-A). So i tried one advice i saw there : booting with nouveau.config=NvForcePost=1 got me no signal instead of a uniform colour. Sorry if i'm actually posting a duplicate, i'm not very experienced with this :) I'll try provide more info if i can.
Created attachment 125293 [details] lspci -v
Created attachment 125294 [details] kernel config in 4.6.4
Observation for Alexandre: This GTX 970 also has 4GB of VRAM. For the OP: you can probably restore your original functionality by booting with nouveau.noaccel=1 nouveau.nofbaccel=1 or alternatively by moving the secboot firmware out of the way (/lib/firmware/nvidia/gm204) temporarily.
Indeed, and the exact commercial model name is "Msi GTX970 Gaming 4G". When booting with : nouveau.noaccel=1 nouveau.nofbaccel=1 i have a normal image on screen when entering KMS, and get my normal high resolution tty. However, i am unable to start Xorg. (attached are the corresponding Xorg.log and dmesg) When you say "moving the secboot firmware out of the way", does it mean i just have to temporarily rename the directory "/lib/firmware/nvidia/gm204" ?
Created attachment 125295 [details] Xorg.0.log file when trying to start Xorg after selecting nouveau.noaccel=1 nouveau.nofbaccel=1
Created attachment 125296 [details] dmesg when trying to start Xorg after selecting nouveau.noaccel=1 nouveau.nofbaccel=1
(In reply to smmilut from comment #5) > Created attachment 125295 [details] > Xorg.0.log file when trying to start Xorg after selecting nouveau.noaccel=1 > nouveau.nofbaccel=1 Fun. Looks like Xorg properly falls back to modesetting (yay), but then just hangs there when trying to initialize glamor. No idea why. I think there's some Xorg config option you can provide to avoid loading glamor. Not sure what it is.
*** This bug has been marked as a duplicate of bug 94990 ***
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