02-04-2016 02:46 PM
I have a P50 (TopSeller 20EN0013US) and dual boot Windows 10 Pro and UbuntuGnome 15.10 with it. I have been having an issue connecting external displays via the laptop's mini-DisplayPort connector. When I plug in an external display while the machine is running, the internal display will begin turning on and off every second, until the external display is disconnected. The external display never turns on. I have the bios set to use dedicated graphics only. I am using the binary Nvidia driver, version 352.63, and have also tried the 352.79, 358.xx, and 361.xx (from the nvidia-drivers ppa) which all have the same issue. I am using the kernel version 184.108.40.206, which is the stock 15.10 ubuntu kernel. The issue does not occur under Windows 10 Pro.
I have been able to work around the issue by setting the mini-Displayport to the primary display device (so it is visible at boot, and ends up being used for the console framebuffer), which then allows me to switch to the console and back, which generally allows both the external display and internal display to work. Any display reconfiguration (or even if the display goes to sleep) will cause the issue to occur again, but I can still switch to the console and back to get it to work.
I also noticed that the issue does not occur via the HDMI output, however all of the displays I personally own only have displayport or dual-link dvi. I have access to a 90W Ultra Dock, which I will try to test tomorrow and see if the displayport's on the dock have the same issue.
Has anybody else ran into this issue? Any suggestions or help is appreciated!
02-08-2016 07:47 PM
I ran in this exact issue on P70 but only when I dock it to pro dock. Connecting external monitor directly to mini DP was not causing flashes in my case. I use gnome-shell and temporary workaround (for flashes) is to restart gnome-shell (I defined a shortcut using .xbindkeysrc for the "gnome-shell --replace".) The flashes stopped permanently only when I saved the monitor setup to its config file manually.
However I gave up and returning P70 for other issues which I couldn't find any workaround. I've just posted to another topic (P50 / P70 linux experiences).
good luck with your installation.
02-09-2016 11:59 AM
04-22-2016 07:49 AM - edited 04-23-2016 09:53 AM
I have been running Fedora 23 on my P50 with dock and external monitors. I ran into an issue like this. Then yesterday I tried installing Ubuntu Gnome 16.04 on it. It was a day of pain. Here are some tips and some other information.
There are three modes the graphics can run in.
1. Intel only(Hybrid in the bios)
It runs like crap, even with workarounds when using external monitors. It also makes using GRUB interactively painfully slow.
2. Intel/Nvidia(Hybrid in the bios)
Kinda worked with external monitors, but when I disconnected from them I wouldn't get a display on the internal display.
3. Nvidia only(Dedicated in the bios)
Had the painful flickering issue to start. Gnome-shell would even crash. Sometimes it would settle down, and work until I wanted to change the monitor configuration. Then it would flicker all over again.
After stumbling on to the fact that 2 wasn't 1 by uninstalling the Nvidia driver. Then I realized that installing the Nvidia driver had installed nvidia-prime. Which is what makes 2 work. I tried uninstalling nvidia-prime, and suddenly the crashing went away.
I still don't have it perfect, but adding this to my xorg.conf seems to have helped get rid continious flicker on display reconfiguration. The numbers 3.2.8, 3.1 and 4 may vary in your case. You should be able to find them from /var/log/Xorg.0.log.
Option "ConnectedMonitor" "DFP, DFP, DFP"
Option "UseDisplayDevice" "DFP-3.2.8, DFP-3.1, DFP-4"
I switched from gdm to lightdm, and the flickering went completely away. It seems to be a bug in gdm. Then I don't need special nvidia options either.
Upgrading to a 4.5.x+(currently 4.5.2) kernel helps with Skylake hardware.
Enabling CSM support in the bios helps. It is basically a backward compatiability mode.
I found a really annoying issue that causes ^@(null characters) to be inputted on the linux console seemingly randomly when connected to the dock. They are inputted like you typed it on the keyboard, so they interfere with typing passwords. I use full disk encryption, and it kept interfering with enter that and logging in during boot. I had to disconnect from the dock most of the time to be able to enter a password. I don't have a solution for this yet.
If you have full disk encryption on like me, and put it in Nvidia only mode the splash screen that asks for your password doesn't work right with Ubuntu GNOME 16.04. It will show your password in the top left as you type it and doesn't seem to take it as input for encryption. I have to use the recovery mode GRUB entry, but take out the word recovery to get it to boot without the splash. Then I can enter the password properly.
04-22-2016 10:24 PM
@ngrennan, thank you for the info on installing Ubuntu 16.04 on P50. I think you can possibly start a new thread on this broader topic. I was trying to install Ubuntu 16.04 on my P50. USB made, and then found a lot of reported issues and I am not sure if I should use LVM to manage the filesystems for Ubuntu...
Back to the topic, do you find any difference using a HDMI and mini-DP for the external monitor?
04-23-2016 09:43 AM
LVM use is marginal. Most of the time it is neither a benefit or detriment. On laptops you aren't likely to want to resize after install. You also don't really have expansion options with most laptops, though the P50 is an exception to that. On the other hand LVM can make things more complicated when doing more advanced things like recovery. My method is not to use it on laptops, and to not even use it on servers(in my case these days that means EC2 instances). The potential exception is database servers. It is useful for doing snapshots. But that is only really useful for ephemeral storage. With EBS volumes you can snapshot them without LVM. It is much more useful on physical servers.
I don't use the HDMI port, and I generally don't use the mini-DP. The HDMI can technically do better than 1080p, but in practice seems to be limited to 1080P. My 1440p monitors will only do 1080p across HDMI. I have a 4k TV, but I have a desktop with a Nvidia 980 that I use with it. My external monitors are 1440p at home and work. While fighting to get the dock to work I have tried the mini-DP, and found if I just want one external monitor the mini-DP works without trouble.
04-24-2016 06:45 PM - edited 04-24-2016 06:49 PM
For those who has problems with the Prime or other NVidia drives, you may want to try Primus: http://www.webupd8.org/2012/11/primus-better-performance-and-less.html
I didn't try it by myself, because I am still having problems with my disks. It is told by others that Primus works better on computers with NVidia. You may need to install Bumblebee before hand: https://wiki.archlinux.org/index.php/bumblebee#Primusrun
04-25-2016 11:10 AM - edited 04-26-2016 09:59 AM
Switching from gdm to lightdm only partially fixed the flickering problem. It would do the same thing when trying to wake up from locking the screen. I found upgrading from 3.18 to 3.20 helped. Then I ran into a crash bug. I fixed it by using a patch from Arch Linux. I asked one of the Ubuntu maintainers to include the patch in the next release.
I seem to still have an issue with coming back from locking the screen, but not the flickering. Fussing with it and waiting on it, it did finally come back and let me login.
3.20 seems to add the lock button back to the top right menu.
16.04 Gnome 3.20 ppa:
04-26-2016 12:44 AM
So, I have tried Primus and it doesn't seem to fix the problem. Still cannot connect to the external monitor stably... Flickering on the build in monitor if connected, and the fans are running heavily some times. It can detect the external monitor, just no image so far...Not sure what is the problem.