After a long search for many many weeks/months, I have found this post. I own a Lenovo T550 and tried different versions of Ubuntu's, to connect to my 2 external Asus PB279Q (4K) via Displayport (1.2). Tried as well via the docking-station and the DP in the laptop itself (connecting both gives me dual 4K @60hz :). Tried monitors also separately/alone, same issue with *exactly the same symptoms* like described here above. Yesterday found, I even downloaded and tried the latest 17.04 (Beta 2), issue is still present.
The screen flickering is random (goes completely black for a few seconds) doing normal browsing work, study, etc. But the blinking considerably occurs much more often, when the terminal window is open. It appears to be occuring depending of the type of content being displayed (e.g. when using phpstorm in 'darcula' mode, it also occurs more). It appears the displayport suddenly goes haywire and switches back. Lowering working-resolution to 2560x1440 and the issue appears to be vanished. I tried as well with the default (standard) driver, as well with the ones I found and installed from 01.org. I work with Ubuntu on user-level, developing web apps. I am handling myself, never did reported these issues, so this is new to me. But since we searched for such a long time without solution found, almost reaching the limits of our patience, I think it's about time and worth to report... (hoping one day for a fix/solution) I know more or less how to reproduce the issue (although it's random, sometimes I need patience, I can let it 'trigger' more quickly), my feedback may be of any help? If there's some kind of instructions I can follow how to pull out relevant logs (I'm not noob, but also not yet a guru...) I can try to pull them out and post them here if wished/required. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1636486 Title: External screen flickers (esp. in terminals) with xorg modesetting driver on Intel Broadwell Status in xorg-server package in Ubuntu: Confirmed Bug description: Hi, I'm using a Dell XPS 13 (9343 // i7-5600U broadwell, 3200x1800 panel) laptop, directly attached to an external Dell P2715Q 4K (3840x2160 @60Hz) via DP. The 4K external screen is flickering when doing light activity -- easily reproduced when using an X terminal. Steps to reproduce: - open side by side Firefox (or Chrome) + a terminal and/or a gvim window on the external 4K screen - do some light web browsing - give focus to the X terminal or gvim // at this point, display is still perfectly steady - press a key to enter a single character // as soon as the key is pressed, external screen goes black for a few seconds. Laptop screen is not affected. - Wait for the screen to come back, then continue typing // screen generally stays ON, but sometimes continues to flicker a few times in next minute. This happens almost every time I switch to the terminal window and start typing. OS specs: - Ubuntu 16.10 running Unity, modesetting Xorg driver - kernel 4.8.0. Issue is still present with 4.9.0rc1. The intel driver (cp /usr/share/doc/xserver-xorg-video-intel/xorg.conf /etc/X11) doesn't exhibit this issue. Also reported upstream: https://bugs.freedesktop.org/show_bug.cgi?id=97264 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1636486/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
