DELL U2717D with RHEL 7.2 'unknown display'

Roland989 · 03-05-2018, 03:02 PM

Hi All,

I'm pretty new to Linux in general, so I'll do my best to ask a helpful question and provide relevant details.

Basically the situation is this: I have recently inherited a Red Hat 7.2 machine (3.10.0-327.el7.x86_64) from a former coworker that I now cannot get in touch with. I don't really know what I'm doing, but I'm picking things up a little at a time.

My problem is the monitor (DELL U2717D) is not being recognized, so the resolution is much lower than it should be. Under Display settings, the monitor is listed as "Unknown Display" with only one resolution option (1024x768) and I can't figure out how to change it. If it's helpful, the monitor is connected via mDP although there is a USB 3.0 option I could try as well.

I've been wrestling with this problem for nearly a month now and I've tried every bit of advice or suggestion that I can find to no avail.

Any help would be greatly appreciated!

Soadyheid · 03-05-2018, 03:25 PM

Redhat is a server distribution and as such does not normally have a monitor attached. You don't mention what sort of system you have inherited. Desktop, workstation, tower server? It would have to have a graphics card installed with the monitor attached (or an embedded one) then you need a graphic driver, not usual in a server distribution. This is possibly your problem. Can you supply details; make and model of you system plus details for the graphic card?

Play Bonny!

Roland989 · 03-06-2018, 08:40 AM

Absolutely, it's a DELL Precision 7910 workstation, and based on this output of lspci

Code:

$ lspci -vnn | grep "VGA" -A 12
03:00.0 VGA compatible controller [0300]: NVIDIA Corporation Device [10de:1bb1] (rev a1) (prog-if 00 [VGA controller])
	Subsystem: Dell Device [1028:11a3]
	Physical Slot: 2
	Flags: bus master, fast devsel, latency 0, IRQ 11
	Memory at f2000000 (32-bit, non-prefetchable) [size=16M]
	Memory at e0000000 (64-bit, prefetchable) [size=256M]
	Memory at f0000000 (64-bit, prefetchable) [size=32M]
	I/O ports at 6000 [size=128]
	Expansion ROM at f3000000 [disabled] [size=512K]
	Capabilities: <access denied>

and some Google searches on that pci id, I believe it has an NVIDIA Quadro P4000 GPU in it.

DavidMcCann · 03-06-2018, 11:33 AM

Have you tried the xrandr command? If it works, just put in in ~/.xinitrc. Your monitor should display at 2560 x 1440 at 60 Hz.

Roland989 · 03-06-2018, 11:41 AM

I have added a new display mode using xrandr (2560x1440_60.00) but after adding the new mode I can't apply it. My current output from xrandr looks like this:

Code:

$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1024 x 768, current 1024 x 768, maximum 2560 x 1440
default connected primary 1024x768+0+0 0mm x 0mm
   1024x768      76.00* 
   2560x1440_60.00  60.00

but when I try to set this new mode I get this:

Code:

$ xrandr --output default --mode "2560x1440_60.00"
xrandr: Failed to get size of gamma for output default
xrandr: Configure crtc 0 failed

mrmazda · 03-06-2018, 07:32 PM

nvidia-settings was probably used to generate an /etc/X11/xorg.conf file that isn't appropriate for your U2717D. Fix may be as simple as either deleting (or renaming) that file and restarting Xorg, or logging out of Xorg, running nvidia-settings from a login on one of the vttys, and restarting Xorg. If neither works, attach the /var/loc/Xorg.0.log file here. It may provide clues to a solution.

Roland989 · 03-08-2018, 01:13 PM

So there is no /etc/X11/xorg.conf file for whatever reason, although there is a /etc/X11/xorg.conf.d/ directory that contains a file, "00-keyboard.conf". Also I get a 'command not found' error when I try to run nvidia-settings, so maybe there's a problem with my video card drivers? I've attached the Xorg.0.log file in case there's something useful in there, but it's a little intimidating for me to look through since I don't know exactly what I'm looking for.

mrmazda · 03-08-2018, 02:08 PM

You definitely have a driver problem. Xorg is using the FBDEV driver, a fallback with extremely limited functionality. /etc/X11/xorg.conf and /etc/X11/xorg.conf.d/* are optional files most users have no need for, though 00-keyboard.conf is very commonly used and desirable.

There are three drivers potentially appropriate for NVidia gfx: 1-modesetting, which is built into the 1.17.2 server reported in your log, typically used by default unless blocked or nouveau is installed; 2-nouveau, a FOSS driver that should be available in standard repos if not already installed; and 3-nvidia, a proprietary driver in very common use. It may be that #3 had been in use before you acquired the machine, but was incompletely removed, and is blocking through blacklisting or other means the automatic use of either #1 or #2. I have negligible experience in NVidia driver eradication, as I never use non-FOSS drivers.

The log reports the kernel cmdline includes modprobe.blacklist=nouveau, so first thing to try is to remove it and try rebooting. Removal can be accomplished via use of the e key when the boot menu appears. If that does the job, then it should be permanently removed from bootloader configuration.

The optimal solution for you might turn out to be replacing RedHat with a more popular distribution. You might be able to upgrade it directly into Fedora, but a fresh installation is probably the best approach, assuming a solution is not found for RedHat.

AwesomeMachine · 03-09-2018, 01:46 AM

Are you able to install software from RH? You use 'yum' for that. Try 'lsmod' and check which modules are loaded. Post the output here.

TB0ne · 03-09-2018, 09:33 AM

Quote:

Originally Posted by Roland989

So there is no /etc/X11/xorg.conf file for whatever reason, although there is a /etc/X11/xorg.conf.d/ directory that contains a file, "00-keyboard.conf". Also I get a 'command not found' error when I try to run nvidia-settings, so maybe there's a problem with my video card drivers? I've attached the Xorg.0.log file in case there's something useful in there, but it's a little intimidating for me to look through since I don't know exactly what I'm looking for.

There typically isn't these days, unless one is generated (like from the nVidia installer). Best suggestion would be to take Soadyheid's post to heart. RHEL is NOT designed for laptops/desktops, but for servers. Things like graphics, bluetooth, sound, etc.....the 'consumer grade' goodies may not work at ALL, or may have to have a considerable amount of tinkering before they work. Add to that the fact that unless you PAY for RHEL, you won't be able to access any of the online repositories, so installing the missing software/modules/drivers will be MUCH harder. There is typically ZERO need to use RHEL on anything but a server. Why are you using it, would be my question?

That said, it appears to use an nVidia Quadro card, and you can install support for that card by installing the driver from the nVidia website. But you will NEED the kernel sources and other stuff (see previous comment about if-you're-not-paying-you-will-have-a-hard-time) first. The driver is easily built, and will generate the appropriate Xorg.conf file and install the new nvidia driver. You will also have to blacklist (maybe) a driver or two to allow the nvidia driver to install. AND you'll have to boot into runlevel 3 (no GUI), to do all of this.

Or, you could just install Fedora (to stay within the RHEL ecosystem), and it'll probably just work out of the box. Your call.

DavidMcCann · 03-09-2018, 11:38 AM

Red Hat is not intended only for servers. And it will work on that computer. There's a post elsewhere by someone who wanted to run Debian on it, complaining that Red Hat 7 and OpenSUSE are the only distros that worked: not Fedora, by the way.

This site is offering drivers for RHEL for both the NVIDIA Quardo and AMD FirePro cards:
http://driversfree.net/drivers/dell-...0-workstation/

TB0ne · 03-09-2018, 12:24 PM

Quote:

Originally Posted by DavidMcCann

Red Hat is not intended only for servers. And it will work on that computer.

Never said it wouldn't work, just that support for such things is difficult. And RHEL *IS* intended for servers, unless you purchase the workstation variant. Red Hat's own notes on their website indicate that. Further, if the OP isn't paying for RHEL, then installing things *IS* going to be more difficult, since (unless it's on the install media), no RHN access will be available. Using RHEL without payment or a genuine NEED is pointless.

Quote:

There's a post elsewhere by someone who wanted to run Debian on it, complaining that Red Hat 7 and OpenSUSE are the only distros that worked: not Fedora, by the way.

Would love to know why, since development in Fedora usually finds it way upstream to RHEL. That machine is nothing special...Xeon processors are well supported, as are all the other devices on that box, based on the specs from Dell's website.
http://www.dell.com/en-us/work/shop/...10-workstation

You can even get the graphic drivers for RH 7 directly from Dell:
http://www.dell.com/support/home/us/...tation/drivers

...where Red Hat 7(server and workstation) are listed, along with Ubuntu. The other poster is obviously mistaken.

Quote:

This site is offering drivers for RHEL for both the NVIDIA Quardo and AMD FirePro cards: http://driversfree.net/drivers/dell-...0-workstation/

I'd much rather get a proprietary driver from nVidia vs. a third-party site.

Roland989 · 03-09-2018, 12:31 PM

I really appreciate all the advice. I tried downloading the Linux drivers for my gpu, with mixed results. On the up side, after installing the drivers the monitor now appears to be the correct resolution. On the down side, every time I boot up it gives me this:

"Oh no! Something has gone wrong.
A problem occurred and the system can't recover. Please log out and try again."

I can still access the ttys, and if I start the X server manually (with "startx") then everything works perfectly. I'm wondering if this might be a problem within the xorg.conf file the NVIDIA driver installer wrote? I'd love to fix this weird startup procedure, but it's at least nice to see my monitor working at all like it should.

Thanks everyone!

mrmazda · 03-09-2018, 12:37 PM

"Oh no! Something has gone wrong" is a message from gnome, usually indicating a hardware or driver shortcoming. The login greeter may offer the opportunity to open some type of session other than Gnome. If so, you may want to try it.

TB0ne · 03-09-2018, 12:50 PM

Quote:

Originally Posted by mrmazda

"Oh no! Something has gone wrong" is a message from gnome, usually indicating a hardware or driver shortcoming. The login greeter may offer the opportunity to open some type of session other than Gnome. If so, you may want to try it.

Agreed. If this is a new installation, I'd suggest logging in as root through a CLI tty window, and removing (or renaming) your home directory. Then create a new, blank one, and be sure to set permissions on it accordingly. If you create it as root, it'll be OWNED by root, and you won't be able to write your configs to it. Usually a "chown <user ID>:<whatever user group> /home/<username>" will do it. Just do an "ls -l" on that home directory first, to see what permissions are and ownership, and match it later.

Try to reboot after that. It's typically a corrupted cache/config with Gnome/KDE/whatever, or .Xauthority is having a problem. New install would be easier to nuke the directory and start over. Renaming it is also good, if you have data, since you can then just copy your data back over, and omit the config directories/files.

I will again, urge caution about using RHEL unless you're paying for it. Your system will wind up being out of date quickly, and you WILL NOT get bugfixes/patches/security updates.