XOrg refusing to start after a fresh build

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Hi,

I'm setting Gentoo up on a new laptop and while I'm not new to this, I am being careful and following the guides. I'm now at a point where XOrg + KDE should be ready to launch, but for the life of me I can't get them to.

The laptop has a Geforce 850M and I'd like to use the official drivers since, annoyingly, I've always found them to have superior 3D acceleration, particularly on newer cards.

acpid, consolekit, dbus, udev, and xdm are all started on boot and their status shows as running.

I opted to install xorg-x11 as opposed to xorg-server to avoid problems with missing fonts etc.

make.conf has nvidia listed both as a USE flag and in VIDEO_CARDS. I also have evdev and synaptics listed as INPUT_DEVICES. /etc/conf.d/xdm has DISPLAYMANAGER="kdm".

I've been over the kernel a good 5,000 - 6,000 times and it's internal DRI / framebuffer support etc are definitely disabled. I've even enabled MTRR cleanup in the kernel, as this system has 16GB memory and https://wiki.gentoo.org/wiki/NVidia/nvidia-drivers#Getting_2D_acceleration_to_work_on_machines_with_4GB_memory_or_more said to switch MTRR to discrete mode in BIOS, which I can't do as this system is UEFI and doesn't offer much in the way of regular BIOS options. Although /proc/mtrr still shows uncachable labels so I'm not sure whether this has helped at all.

With X installed, I then installed KDE via the kdebase-meta package, and a couple of the other -meta packages. Normally I'd go for kdebase-startkde and individual program names but ironically I figured if I just bring in the meta's I'll know I'm not missing anything important, and it'll all just work :roll:

Everything installed smoothly, OpenGL and OpenCL are both set to nvidia and as this is a newer card I've added vdpau to the USE flags and performed a world update.

Rebooting resulted in a black screen. switching ttl and attempting to startx resulted in "No screens found" so I ran /opt/bin/nvidia-xconfig to generate an xorg.conf (Had to be done as root because /etc/X11/xorg.conf wasn't writable to all, although the guide states user).

Another reboot, just to be sure, and again a black screen. Still no luck.

Adding BusID to the Device section of xorg.conf seems to have fixed the no screens output when I startx, but now I get the following output:

NeddySeagoon · Posted: Thu Jan 15, 2015 7:56 pm Post subject:

qweb.ric,

Welcome to Gentoo.
You have the right approach. Build on what you know works

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Hi Neddy,

I've removed xdm from RC, emerged xterm, xclock, and twm, and rebooted to be sure there's nothing running.

startx now gives no errors, obviously, but still just results in a blank screen. Even if I amend the DISPLAYMANAGER line of /etc/conf.d/xdm to load twm.

I'm now thinking if KDM/XOrg isn't the issue, then it must either be nvidia-drivers, which I find unlikely given I've tried numerous builds now, or the framebuffer. I've disabled the nvidia framebuffer from the kernel, as per the instructions though so it should be the nvidia-drivers framebuffer that's in use now... So either way I suppose it's the driver that's not working?

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

Assuming the card is compatible with nouveau (I haven't checked and don't know) you might just want to go ahead and try installing with that and getting things operational. Then you can always change it later. It's not all that hard to change really although you will have to recompile some programs. Who knows you might find Nouveau works well for you. I have older hardware (Quadro FX 570) but it actually seems to perform better for normal desktop usage for me with Nouveau as opposed to the binary driver which seems sometimes a bit buggy in its support.

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Hi David,

I keep considering that, and for the sake of testing I really should do, but to be honest I just can't see nouveau working out for me. I chose the 850M because I need a heavy graphics unit (Photoshop inside Virtualbox inside KDE, usually with a couple of other VM's running in parallel as I do a lot of switching between the various operating systems for testing, all at 1080p. OK maybe I don't need KDE, but that's become the environment I'm comfortable working in). As much as I love open source, I'm just not confident that a backward engineered driver can use this card to it's full potential.

DONAHUE · Posted: Fri Jan 16, 2015 12:14 am Post subject:

make and model of the laptop?
suggest pastebin /var/log/Xorg.0.log, /usr/src/linux/.config, and outputs of dmesg and lspci -k
_________________
Defund the FCC.

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Hi,

It's a custom built laptop but here's the related spec:

2.5GHz Intel i7 quad core (4710MQ)
16GB DDR3 memory
2GB GeForce GTX 850M

dmesg does show this interesting snippet:

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Ahh, I now understand why this isn't working!

This system is using nVidia Optimus which seems to mean that the Geforce isn't actually connected to a screen, which explains those odd messages in dmesg and XOrg.conf... It also means neither nvidia-drivers or the open source drivers work out of the box - I actually stumbled on to this information while reading over the nouveau guide.

Frustratingly, I've now managed to totally kill this laptop while switching it to use the in-kernel nvidia framebuffer ready for nouveau so now I just have a black screen, even during boot, and I'm currently in the office with no live disk so I can't yet get back into it. Here are the options though, for anybody else experiencing this issue:

Use the nVidia card but xrandr the output over to the on-board chipset, which I fear defeats the purpose of Optimus entirely: https://wiki.gentoo.org/wiki/NVIDIA_Driver_with_Optimus_Laptops

Or use Bumblebee which seems to do the same thing but only when you tell it to, meaning the rest of the time you're using integrated graphics. This project seems to no longer be maintained though, and probably a headache to use: http://www.bumblebee-project.org

Until Optimus just works natively via nvidia-drivers or the kernel, I suppose I'm going to have to go the xrandr route.

I'll update this thread with the results.

NeddySeagoon · Posted: Fri Jan 16, 2015 9:09 pm Post subject:

qweb.ric,

The idea is that the Intel chip drives the screen refresh at all times.
Thats not very strenuous, its just constantly reading the pixel buffer to the screen. All video chips have that capability.

With the Optimus graphics solution. you get to choose which chip draws into the pixel buffer.
The Intel one is less capable and less power hungry, or the nVidia one, which gives you the nVidia performance you want.
Its drawing the image that is the hard work.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

Hi,

The xrandr method actually does seem to work quite well. KDM was rendered at 640x480 and tiled across my 1920x1080 screen until I added a Virtual line to the xorg.conf, I had to also add modesetting as a graphic card in xorg.conf which the guide didn't mention, and I totally forgot to rebuild nvidia-drivers after a couple of kernel rebuilds, causing a good 4 hours of headache, but now that I'm in I'm impressed!

17,000 fps at 1920x1080 according to glxgears and running at about 42degC which seems reasonable. There doesn't seem to be any vsync option but I'm not so fussed about that.

Thanks for the help guys.

wgjak47 · n00b Joined: 04 May 2014 Posts: 14

qweb.ric · n00b Joined: 15 Jan 2015 Posts: 29

You just need to move your Display subsection from the intel screen to the nvidia screen. You may also need to add a BusID to your intel device like you have with the nvidia device - I did.

My xorg.conf is as follows:

wgjak47 · n00b Joined: 04 May 2014 Posts: 14

Thanks, I have solved this problem.