Help! Kde Plasma 5 nvidia multi-monitor

cctsurf · Tux's lil' helper Joined: 12 Oct 2006 Posts: 123

First dumb question, in a google search, how do you specify that you are looking for kde plasma 5? if I look for just kde or plasma, I get hits for plasma 4 as well... I could use "kde plasma 5" or "plasma 5" or Plasma-5, but those options don't seem to produce the best results. I've resorted to limiting my searches to the last year, but that is not great, either.

I've been running kde since the late '90s. I also love having multiple monitors, the more the better... It really helps me get work done. I remember back in the day with mode lines, etc, but I could usually get my hodgepodge of monitors working with the right xorg.conf foo.

I had tried to make the jump to plasma 5 a while ago and got nowhere. After the splash screen, it just froze on a black screen with a mouse cursor... I had numerous segfaults, I thought I had a dependency problem and rebuilt the system. Reading that it could be .config files in my user directory, I backed them up, but again nothing. Finally after trying to get it going for quite a while, gave up and rebuilt kde4.

Recently, I was encouraged that my (~80 year old) dad was using and enjoying all of the plasma 5 goodness, and built plasma 5 again. Same issue, except this time, I prevailed to get a simple monitor configuration working. (I realize that the problems I had earlier was to do with monitor xorg monitor configuration) YAY! So, now I'm hoping I can get all 6 of my monitors working.

Here's the deal:
As soon as I have more than 1 "screen" on X, I no longer have picture on the secondary screen. If I combine multiple displays into one "screen" (up to 4 right now), I have picture on those displays. Other "screens" are reachable with the x mouse cursor, but they are not controlled by the display manager. xinerama produces the above issues with segfaults and blank screens. (I thought this was supposed to be fixed -- https://bugs.kde.org/show_bug.cgi?id=343844)
In the "display configuration" under "system settings," the the displays in the "screen" show up individually (though they are combined as one screen under the xorg.conf), but the other displays don't show up. I downgraded nvidia-drivers to 355.11-r2 to allow me to use nvidia-settings-355.11. In nvidia-settings, I see all of the screens, but no matter how I configure them, either get segfaults or blank screens.
I have attempted using "mosaic" with no help.
I have an nvidia setup with 2 610 cards. On each card, I have 3 monitors attached. I use the system for writing and mild video work, so I suppose I could try the nouveau drivers, but I like the video acceleration available through nvidia-drivers.

In my opinion, plasma-5 is not ready for production, I really wish the kde4 would continue to get some love. In addition to this issue, a number of the apps are not available or in beta/alpha state. I remember by the time kde4 was at 4.5 version, we had a usable system.

Any thoughts? I guess one question is, is this a bug that should be posted or am I just missing a mode in which I could get this working?

davidm · Guru Joined: 26 Apr 2009 Posts: 557 Location: US

Well just a small note. I have heard that with qt 5.6 there will be several important fixes to multi-screen support so it is possible things will be better for you when that occurs.

Like you, unfortunately, I found some problems with Plasma 5 (both plasma and actually interaction with other drivers such as the GPU) so I am staying with kde4 for now.

radio_flyer · Posted: Sat Jan 02, 2016 4:00 am Post subject:

I'm running KDE4 and open-source radeoon drivers, so probably not applicable. However, I do run three monitors, and occasionally I've had System Settings-->Display And Monitor-->Display Configuration go totally bonkers. In those cases deleting the files in .kde4/share/apps/kscreen and then logging back in seems to restore sanity and allows me to reconfigure my multi-monitor setup correctly. Like I said, probably not applicable in your case, but FYI.

cctsurf · Tux's lil' helper Joined: 12 Oct 2006 Posts: 123

I appreciate your assistance, radio_flyer, but yes, it is a long way from the nvidia binary drivers on kde plasma 5 to the open-source radeon drivers on kde4. I've been running kde4 with the nvidia drivers on this system with these 6 monitors for quite some time with absolutely no problems, but as soon as I upgrade to plasma 5, it fails. I've attempted both the kde overlay and the ebuilds in the tree with the same results. I've used some of my previous experience to gain limited control over the two remaining monitors from virtual terminals

cctsurf · Tux's lil' helper Joined: 12 Oct 2006 Posts: 123

Now that plasma5 is "stable" has this been helped? I really don't want to upgrade if my monitors won't be under plasma control.

radio_flyer · Posted: Tue Apr 12, 2016 5:22 pm Post subject:

I upgraded to KDE 5 this weekend after the portage KDE news came out declaring Plasma 5 stable (and KDE4 abandoned upstream). After resolving the usual major upgrade headaches (restoring all my old configurations etc.) my triple-monitor system is now running fine with KDE 5 on my Radeon card with the open-source driver. Virtual desktops, etc., all seem to be working. Note that with KDE 5 you can still have different wallpapers on different monitors, but not on different virtual desktops.

Like davidm noted, you might want to wait for Qt 5.6 to hit portage if you're using the Nvidia or Intel drivers. My web-searching this weekend came across a number of folks having multiple-monitor issues with KDE 5 that apparently relate to bugs in the drivers interacting with Qt, and supposedly fixed in 5.6.

cctsurf · Tux's lil' helper Joined: 12 Oct 2006 Posts: 123

Well, QT 5.6 is out... I thought I would try to make it work again. No help so far. Further research shows that the problem is with Plasma, Nvidia, Xrandr and multiple graphics cards.
https://bugs.kde.org/show_bug.cgi?id=343844
Made some progress by forcing the nvidia driver to interract with xorg through xrandr, which has been built into the more recent nvidia-drivers versions. I have good access to the 4 screens that are on my main graphics card, but no picture or anything on my other graphics card and its two monitors.
I went through all sorts of machinacians of xrandr command lines, but nothing. It shows the monitors as disconnected.

radio_flyer · Posted: Fri Apr 29, 2016 7:23 am Post subject:

You're not really missing anything, other than not having to constantly close the baloo_file crash window or watch your panel randomly jump to another monitor occasionally after logging in.

Eerily similar to the KDE3 to KDE4 transition.

cctsurf · Tux's lil' helper Joined: 12 Oct 2006 Posts: 123

Well, I've been running a kde4 system using the information found here: https://forums.gentoo.org/viewtopic-t-1028648.html It was working great until the last couple of days, the updates were coming in and the KDE4 builds were going missing... What to do, what to do...
I took the plunge again, unmasked everything I had masked and followed the wiki on upgrading to plasma, and I have a working multi-head, dual-card nvidia system using the nvidia binary blobs and xinerama!
I was really dreading doing this upgrade. I was cussing the developers because they had forced me into it, but it finally worked. I have all 6 monitors working.
There are a couple of things to iron out, the screens are treated as one big screen without any deliniation between them... i.e. I cannot maximize to one monitor, it goes across all of them. But I was expecting to have to install an alternate operating system or a different desktop environment to keep my multi-screen goodness going...But it finally works!
Thanks Guys, I hope this helps someone else out
cctsurf

The_Great_Sephiroth · Posted: Sun Jul 10, 2016 2:57 pm Post subject:

I hate to bear bad news, but we cannot even get a simple two-monitor setup working in KDE5. What I discovered was that if you place any monitor other than the primary monitor above or to the left of the primary monitor, all hell breaks loose. I use a Latitude laptop for work (as does my boss) and our primary monitors are the ones built into the machines. They are called LVDS unless I am mistaken. We both hook up external monitors when at our desks. Mine is to the right of my laptop and works flawlessly. His is to the left, and if he disconnects it or even shuts down, leaves, and boots up without it after configuring it to the left of his laptop monitor, the screen is garbled and the mouse cannot move from the upper-left corner.

We too are waiting for a fix since KDE4 was perfect and never gave us any trouble. We also miss the multiple desktops with different wallpapers and all. KDE5 was tad of a step backwards, but when it works it is nice.
_________________
Ever picture systemd as what runs "The Borg"?

Josejnc · n00b Joined: 12 Aug 2016 Posts: 1

Actually I have a multi-monitor config that works.

I can made it work in X in all forms. I have two graphics cards and two monitors. X can be correctly configured to work with all combinations of monitors that works on the motherboard but Plasma only recognize the Bios primary card. So If I make the bios start from Card1 I can use KDE on the monitors connected on monitor1 and a X configured screen on the other. If I put card2 on the bios then I can only use kde on monitor 2.

That is INDEPENDENT on the interface. DVI, VGA, HDMI, so is a kde problem..

So the problem is not multi-monitor but multiple graphics cards.
f someone can help with it I would be grateful.

PD I am not a English native.