[SOLVED] NVIDIA and nouveau driver, some basic questions

[sanmig]

Regarding the thread: viewtopic.php?p=1759275&sid=2e64c577ed3 ... b#p1759275
I’d like to know how to read / understand inxi, Driver Manager and “dmesg | grep nouveau” output. Where does it come from?

@GrassWhooper’s inxi -Fxz reports (I guess booting from installed 19.3):
Graphics:
Device-1: Intel vendor: Lenovo driver: i915 v: kernel bus ID: 00:02.0
Device-2: NVIDIA vendor: Lenovo driver: N/A bus ID: 01:00.0
Display: x11 server: X.Org 1.20.4 driver: modesetting unloaded: fbdev,vesa
resolution: 1920x1080~60Hz

1)
So there would be 2 devices -
- One on the CPU (i7-9750H), the other a dedicated card (GTX 1050 3 GB, why are type and driver not mentioned in inxi?)?
- What is "Lenovo driver: N/A", part of Linux Mint?

In contrast, my inxi (installed 19.3) reports only 1 device, the GTX 750 and the driver 435.21 (but my i5 has internal graphics, too).

2)
My Driver Manager (requires privileges to check?) shows 435.21 (recommended) is installed.
@GrassWhooper’s DM - I dunno.

3)
Both, @GrassWhooper’s and my dmesg | grep nouveau don’t give any result, OK -
- Does it mean nouveau driver is not installed?

See @GrassWhooper’s “nouveau: probe … failed with error -12”
(I have “nvidia: module verification failed … tainting kernel” ? )
- Does it mean @GrassWhooper’s system tries to install nouveau, but failed?
- Which driver is loaded then?

But I'm curious ...
Booting 19.3 from USB my system reports:
A)
inxi -Fxz:
“Device-1 GTX 750, driver: nouveau v: kernel “ - Seems to be OK (?).

B)
Driver Manager:
“Failed to download repository information - Check your Internet connection.”
Details:
“E:The repository ‘sdrom://Linux Mint 19.3_Tricia_-Release amd64 20191213 bionic Release’ does not have a Release file.”
- OK, but, uh? Whom to inform?

Anyway, after “Close” the Driver Manager reports “xserver-xorg-video-nouveau (open source)” installed - seems to be OK for OSS (“No proprietary drivers are in use.”).

C)
dmesg | grep nouveau:
Several lines with "nouveau", and confirms NVIDIA GM107 installed.

However, as I’m always curious:
Just to test my system I’ve changed in the Driver Manager from nouveau to recommended nvidia 435 :
OK, Applying changes … takes quite some time …
After grabbing a coffee Driver Manager is back, confirming 435 (recommended) is in use.
Both, inxi and dmesg still report nouveau !
Closed Driver Manager, reopen:
Still shows nvidia 435 in use.
- So what is correct now?

OK, it may be impossible to change the graphics driver in the live system, but the Driver Manager shouldn’t pretend to have changed it?

[zcot]

Regarding the thread: viewtopic.php?p=1759275&sid=2e64c577ed3 ... b#p1759275
I’d like to know how to read / understand inxi, Driver Manager and “dmesg | grep nouveau” output. Where does it come from?

@GrassWhooper’s inxi -Fxz reports (I guess booting from installed 19.3):
Graphics:
Device-1: Intel vendor: Lenovo driver: i915 v: kernel bus ID: 00:02.0
Device-2: NVIDIA vendor: Lenovo driver: N/A bus ID: 01:00.0
Display: x11 server: X.Org 1.20.4 driver: modesetting unloaded: fbdev,vesa
resolution: 1920x1080~60Hz

1)
So there would be 2 devices -
- One on the CPU (i7-9750H), the other a dedicated card (GTX 1050 3 GB, why are type and driver not mentioned in inxi?)?
- What is "Lenovo driver: N/A", part of Linux Mint?

In contrast, my inxi (installed 19.3) reports only 1 device, the GTX 750 and the driver 435.21 (but my i5 has internal graphics, too).

Here's the info from that line:
Device-2: NVIDIA
vendor: Lenovo
driver: N/A
bus ID: 01:00.0

There is an issue on that system. This is not good correct output like a properly functioning system would show, -there is some problem here.

2)
My Driver Manager (requires privileges to check?) shows 435.21 (recommended) is installed.
@GrassWhooper’s DM - I dunno.

yes, you would be modifying system file space using the Driver Manager and so that does require elevated permission.

3)
Both, @GrassWhooper’s and my dmesg | grep nouveau don’t give any result, OK -
- Does it mean nouveau driver is not installed?

See @GrassWhooper’s “nouveau: probe … failed with error -12”
(I have “nvidia: module verification failed … tainting kernel” ? )
- Does it mean @GrassWhooper’s system tries to install nouveau, but failed?
- Which driver is loaded then?

GrassWhooper is making an error. The output definitely does contain info about "nouveau", maybe he misspelled it or in some way didn't type the command correctly. The example line shows “nouveau: probe … failed with error -12” so at the very least that command would show that line.

dmesg is a command by itself. Try it out and you'll see.

piping the output(using | character) will let you further process that output from the dmesg command.

In this example grep was used to filter out only the lines that contained the text "nouveau". check out command grep --help

try this: dmesg | grep 'Linux version'
try this: dmesg | head (default is 10 lines, you can check head --help or man head to get further)

Anyway, yes for GrassWhooper it tried to load nouveau and failed and the result is that now there is not a good correct driver for that nvidia gpu, so it would end up using some vesa/mesa generic mode(some basic ability gpu module that the kernel can fall back to in worst case scenario) if the gpu was in use, which it is not in use. You can tell by looking at the last line, the one you did not quote, that shows the Opengl renderer and it shows the intel implementation.

But I'm curious ...
Booting 19.3 from USB my system reports:
A)
inxi -Fxz:
“Device-1 GTX 750, driver: nouveau v: kernel “ - Seems to be OK (?).

A live system will try to load nouveau if it detects nvidia gpu hardware. Yes, correct.

B)
Driver Manager:
“Failed to download repository information - Check your Internet connection.”
Details:
“E:The repository ‘sdrom://Linux Mint 19.3_Tricia_-Release amd64 20191213 bionic Release’ does not have a Release file.”
- OK, but, uh? Whom to inform?

The repository for a live session is the "cdrom", or actually DVD or the USB stick, and the live session is not meant to be a fully functioning system.

Anyway, after “Close” the Driver Manager reports “xserver-xorg-video-nouveau (open source)” installed - seems to be OK for OSS (“No proprietary drivers are in use.”).

that's fine, on live session or installed. nouveau is a functional default gpu driver setup.

C)
dmesg | grep nouveau:
Several lines with "nouveau", and confirms NVIDIA GM107 installed.

nouveau driver is installed. it is calling the device GM107

However, as I’m always curious:
Just to test my system I’ve changed in the Driver Manager from nouveau to recommended nvidia 435 :
OK, Applying changes … takes quite some time …
After grabbing a coffee Driver Manager is back, confirming 435 (recommended) is in use.
Both, inxi and dmesg still report nouveau !
Closed Driver Manager, reopen:
Still shows nvidia 435 in use.
- So what is correct now?

yes. Well, reboot, and you get the more accurate inxi info. If not, then there is a problem. Most often it will end up with horrible graphics resolution and/or some inxi output that looks like GrassWhooper.

OK, it may be impossible to change the graphics driver in the live system, but the Driver Manager shouldn’t pretend to have changed it?

yes. the live session is simply a magic extension of the installation system, it is temporary and does not function completely as would be while fully installed.

[sanmig]

Thanks for your detailed reply!

yes, you would be modifying system file space using the Driver Manager and so that does require elevated permission.

No, on the contrary, from my point of view it puts the horses before the carriage:
When opening Driver Manager it means I want to check what’s going on.
I could even select an other driver, but with “Apply Changes” the permissions would be required.
This is how it should work - and in fact works in (most) other places.
The “problem” here is with useless asking for permissions the user will be either scared or annoyed and finally careless.
Don’t!
(But I don’t know where to complain)

For the “dmesg | grep”, as I’m curious, I’ve read man-pages + of all parts of that line, of course didn’t understand everything. So thanks anyway, it confirms what I “thought” it would do.
What e.g. I did not understand is who writes what into that ring buffer, is it “The Truth” or does it in any form depend on the third party SW (e.g. a typo “noveau” in that SW and it would be missed?)?

Anyway, yes for GrassWhooper it tried to load nouveau and failed and the result is that now there is not a good correct driver for that nvidia gpu, so it would end up using some vesa/mesa generic mode(some basic ability gpu module that the kernel can fall back to in worst case scenario) if the gpu was in use, which it is not in use. You can tell by looking at the last line, the one you did not quote, that shows the Opengl renderer and it shows the intel implementation.

- This is a very interesting part, although, lacking background, I did not understand fully:

Live session kernel detects NVIDIA, tries to load nouveau, uses - exactly what?
I’d expected the output would be the basic 80 by 40 black and white text reading “can not load a driver for your NVIDIA card, do you want to continue anyway?” or similar.
I’m not really happy about booting into something at least questionable without explicitly warning the user.
And regarding the Opengl renderer - I’m afraid that’s above my head …

Anyway, running the live system for some days would have revealed basic issues before installing Mint!

Re Driver Manager:
Now, sorry, comes one of my pet issues:
A Warning without valid reason (?):
“E:The repository ‘sdrom://Linux Mint 19.3_Tricia_-Release amd64 20191213 bionic Release’ does not have a Release file.”
And the “Check your Internet connection”, pointing at an innocent to cover the own mistake, is the topping on the cake.
“Anyone who simply swallows that has already given up his self-respect.”
(According to a saying by Karl Lagerfeld)
- Give it a release file or do not warn that it’s missing! (and never point at the neighbour first)

***
- I’m still chewing on your “the live session is not meant to be a fully functioning system”.
I did not read or know about that.
Rebooting will restart the live session, loading nouveau, so …

After changing the driver in the (live) Driver Manager, is it already active or does it take a reboot to get the “promised” driver to run? Without a hint to reboot?
I mean, if it is actually loaded, then neither inxi nor dmesg would show what is really loaded?

I’m really sorry for my curiosity, I feel like a child that can’t stop asking to get a glance of the world it lives in

Thank you for your patience!

[zcot]

No, on the contrary, from my point of view it puts the horses before the carriage:
When opening Driver Manager it means I want to check what’s going on.
I could even select an other driver, but with “Apply Changes” the permissions would be required.
This is how it should work - and in fact works in (most) other places.
The “problem” here is with useless asking for permissions the user will be either scared or annoyed and finally careless.
Don’t!
(But I don’t know where to complain)

On an installed system, but not live session / test environment / temporary system, sure, I can understand the point. Here is the repository for Mint Driver Manager, and you check in the "Issues" section, for existing problems / questions / bugs / etc. : https://github.com/linuxmint/mintdrivers

For the “dmesg | grep”, as I’m curious, I’ve read man-pages + of all parts of that line, of course didn’t understand everything. So thanks anyway, it confirms what I “thought” it would do.
What e.g. I did not understand is who writes what into that ring buffer, is it “The Truth” or does it in any form depend on the third party SW (e.g. a typo “noveau” in that SW and it would be missed?)?

the kernel is the one writing that information, in this case. (there are other usages for dmesg, but the default is viewing kernel related info) It is "the truth". If it says nouveau is loaded, then nouveau is loaded, if it says nvidia is loaded then nvidia is loaded, if it is blank or says N/A then there is some problem and and either a generic mesa mode is being used(the full dmesg info would show exactly what module is in action and what it's doing) or maybe with dual gpu then it is not even in use.

You are not going to find some typo like that. The typo will be found by the end user like in the previous example GrassWhooper showed a clear error message from dmesg but then said nothing was returned from typing the query command. It was 100% not the kernel being wrong about that info, because we already saw the truth before that.

- I’m still chewing on your “the live session is not meant to be a fully functioning system”.
I did not read or know about that.
Rebooting will restart the live session, loading nouveau, so …

After changing the driver in the (live) Driver Manager, is it already active or does it take a reboot to get the “promised” driver to run? Without a hint to reboot?
I mean, if it is actually loaded, then neither inxi nor dmesg would show what is really loaded?

The live session is not going to load the nvidia proprietary driver.

The live session is a read only system.

Opening the Driver Manager on a live system is not even worth it.

[sanmig]

Thanks for pointing at the Mint Driver Manager, but sorry, where Mi$o is in, I’m out.

So the live system “is what it is”, and it doesn’t make sense to check (as I did back in 2018 before deciding to install Mint ) if a different (proprietary) graphics driver would run with my GPU (nouveau had a bad image of wasting energy at that time).
I must have confused that with a different (smaller) Linux edition which had an option to run from RAM. (*)

Thank you for helping to understand, to learn about Linux is a bummer for a n00b!

(*)
You seem to be deeply involved in development, FWIW, let me add one last suggestion:
The first line of the GRUB live boot menu simply reads:
“Start Linux Mint”.
It would be great to add “Live Session (read only)” or “from CD/USB (read only)” or even without the (read only) - but it's more than non - persistent.

[zcot]

So the live system “is what it is”, and it doesn’t make sense to check (as I did back in 2018 before deciding to install Mint ) if a different (proprietary) graphics driver would run with my GPU (nouveau had a bad image of wasting energy at that time).
I must have confused that with a different (smaller) Linux edition which had an option to run from RAM. (*)

Well, you could test a proprietary nvidia driver on a live system, however, you just can't do it using the Driver Manager. And it's advanced, and it requires configuring special booting, and modifying the live session file system. And you could run the whole thing from ram too. But, for most, that's too much of a waste of time and/or too advanced to want to deal with for a test system. And also because we already know the nvidia driver will run on nvidia hardware so it seems like there is not so much to gain from having to go through all that.

For many, maybe most, the live session is a near perfect temporary session, where all the hardware is functioning and acting correctly.

But there are cases where it doesn't work without maybe at least supplying a custom boot parameter for the kernel or even having to get crazy and do a bunch of research and figure out some cryptic line of like 7 or 8 kernel parameters... -oh, well there's "compatibility mode" for that which takes care of almost all of those situations.

As for the "live session", this is using the files of the regular install system, so modifying the files for live would mean creating a different enough system where those files couldn't be used for an installation then without modifying them, or having duplicate files that worked with each of the sessions respectively. The installation guide does mention it: https://linuxmint-installation-guide.re ... stall.html I get your point though about having a different live system as a test system, instead of using the regular files for a live session.

[sanmig]

And also because we already know the nvidia driver will run on nvidia hardware so it seems like there is not so much to gain from having to go through all that.

OK, that’s very comforting to all the GrassWhoopers out there

Um, no, I was never thinking of “a different live system as a test system”. To maintain two slightly different versions is a more than double burden as maintaining one. The live system is good as it is.
Complexity is a killer, adding confusion is evil.

But still today when reading the installation guide I would not understand it as a “read only” and “not fully functioning” system.
It says:
“Changes you make in the live session are not permanent.” - OK
It doesn’t say “… are not possible” (which wouldn’t be true anyway).

Bad is the Driver Manager’s “changing” the driver for minutes, silently coming to an end, without realising that all the work was in vain.
And the user has no (GUI) chance to realise he was fooled:
Checking back the DM even confirms the new driver is in use.

... Watching that makes the hair stand up in the back of my neck
Deep issues often come in silently.
It is hard to believe this (basically unacceptable) behaviour is only because “some applications work differently” in the live system, respectively when installed, a similar issue would be detected by the DM / system.
Probably there is a structural problem that will bite again later in a different situation?
Why suppress the “You need to restart the computer to complete the driver change” in the live system? After restart from CD/USB it would be obvious that changing can’t work.

But honestly, I don’t want to complain in most of my postings, knowing about the hundreds of experts working in their spare time to push Linux to the desktop of the average user, to use it “for free”, and the progress Linux made and will continue to make by the help of enthusiasts.
- Here is the very specific reason why I hate Mi$o: Missing fairness.
They’ve already sold their OS even when the machine ends up running Linux!
(exceptions confirm the rule)

Re desktop OS:
Of course you are the one to use the command line to change your GPU driver.
But please try the DM GUI in an installed 19.3 system:
Change the driver from NVIDIA to nouveau, apply, but not restart!
Instead, change back to NVIDIA, apply, back and forth, apply, no restart!

Now simply close that window by “X”.
(scary, but it is possible …)

Restart, then start the DM.
You’ll see a (forever) broken DM, “updating cache”, neither giving “Details” nor showing which driver in use, an empty window - Let alone a possibility to change the driver again.
It only reads: “No proprietary drivers are in use.”
- That’s what I have now.

No worries, beeee happy … because it’s not true:
inxi -Fxz knows: It’s nvidia 435.21,
confirmed by dmesg | grep “nvidia”

So I’ve really learned a lot by your help, thanks again for your patience!