Created attachment 138747 [details] screenshots 1) Tested on Ubuntu 14.04, 16.04, 17.10, Debian 8, Tails (0.2,...,6.2), Kali... and some other Linux distributions. 2) The computer is a Dell laptop with a built-in NVIDIA Quadro FX 2500M (identified as NVIDIA Corporation G71GLM) 3) Kernel driver in use: nouveau 4) Everything was worked fine using the nouveau driver but someday the screen backlight failed and I have to replace the broken WUXGA+ screen with a new one, same specifications except is a glossy screen (not matte). The screen product numbers are almost identical (New screen: Samsung LTN170U1-L02, Old one: Samsung LTN170U1-L01). 5) With the new screen installed the display is corrupted as it shows in the attached pictures. The vertical resolution (1200px) seems to be fine but the horizontal pixels (1920x) are distributed doubling the width (the right half out of the screen). The desktop is chopped and the screen is full of scan flicks, errors and artifacts. 6) No issues using NVIDIA propietary driver.
If "vertical" is OK, that means the screen is OK and nouveau's modesetting is OK. (The rotation is purely software, it's still a 1920x1200 framebuffer.) Could something else have gotten updated? Can you grab a copy of dmesg and xorg logs? What version of mesa is being used? I presume all your woes go away when booting with nouveau.noaccel=1.
Created attachment 138876 [details] matte.Xorg.0.log
Created attachment 138877 [details] matte.dmesg.log
Created attachment 138878 [details] glossy.Xorg.0.log
Created attachment 138879 [details] glossy.dmesg.log
Thank you very much. I have finally managed how to deal with the scrambled display using the new glossy screen. These are the requested logs: 1) Using the broken matte screen (Samsung LTN170U1-L01) (with this screen the driver works as expected) --- attachment matte.Xorg.0.log --- attachment matte.dmesg.log 2) Using the new glossy screen (Samsung LTN170U1-L02) (with this screen the driver does not work properly) --- attachment glossy.Xorg.0.log --- attachment glossy.dmesg.log > I presume all your woes go away when booting with nouveau.noaccel=1. As the listed OS are Live USB OS I don't actually know how to boot with this setting.
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