On-demand and RTD3 need to be separated

[jeremyszu]

RTD3 is a nvidia GPU feature to support runtime suspend.

On-demand would be a X offloading feature.

They are independent, according to discussion on https://github.com/tseliot/ubuntu-drivers-common/issues/55.

Some parts need to be adjusted, e.g.

```
    # If we are dealing with NVIDIA PRIME, and runtimepm
    # is supported, enable it
    if (os.path.isfile('/run/nvidia_runtimepm_supported') and
        os.path.isfile('/usr/bin/prime-select')):
        print('Trying to select the on-demand PRIME profile')
        try:
            subprocess.call(['prime-select', 'on-demand'])
        except:
            pass

        # Create the override file for gpu-manager
        with open('/etc/u-d-c-nvidia-runtimepm-override', 'w') as f:
            f.write('# File created by ubuntu-drivers\n')
```

---

[Impact]

 * Ubuntu will set GPU mode to performance as default which may use more power
 * User can't use GPU for other purpose (eg: deep-learning) if RTD3 is not supported
 * According to Nvidia README, the RTD3 doesn't support on non-laptop machine

[Test Plan]

 * Install Ubuntu, and then execute 'ubuntu-drivers install' to install GPU driver. After the installation, reboot the system. Execute "prime-select query" should get "on-demand"
 * Old GPU (which supported by nvidia-390 only) will keep in performance mode, refer LP:1957094. Execute "prime-select query" should get "nvidia"
 * On non-laptop machine. Can set GPU mode to on-demand
 * On laptop with GPU in runtime PM support list. Set GPU mode to on-demand and Nvidia driver is loaded with "NVreg_DynamicPowerManagement=0x02"

[Where problems could occur]

 * With GPU supported RTD3 not able enable runtime PM on non-laptop. But based on the Nvidia README, this case shall not happened.

[Other Info]

Changelogs:

nvidia-prime (0.8.16~0.20.04.2) focal; urgency=medium

  [ Jeremy Szu ]
  * Set on-demand mode as default nvidia mode (LP: #1942307)

  [ Alberto Milone ]
  * prime-select:
    - Detect chassis type and enable RTD3 only
      on laptops (LP: #1942788).
    - on-demand mode doesn't need to depend on
      RTD3 (LP: #1942789).
    - Use bootvga detection when last_gfx_boot
      is not available.
    - Don't check the current profile when setting
      a profile (LP: #1946476).
    - Handle BrokenPipeError (LP: #1965520).

[Launchpad Janitor (janitor)]

This bug was fixed in the package nvidia-prime - 0.8.17

---------------
nvidia-prime (0.8.17) impish; urgency=medium

  [ Jeremy Szu ]
  * Set on-demand mode as default nvidia mode (LP: #1942307)

  [ Alberto Milone ]
  * prime-select:
    - Detect chassis type and enable RTD3 only
      on laptops (LP: #1942788).
    - on-demand mode doesn't need to depend on
      RTD3 (LP: #1942789).
    - Use bootvga detection when last_gfx_boot
      is not available.

 -- Alberto Milone <email address hidden> Fri, 17 Sep 2021 16:45:11 +0200

[jeremyszu (os369510)]

@Alberto,

Could we please apply them to focal as well?

[Brian Murray (brian-murray)]

Thanks for uploading the fix for this bug report to -proposed. However, when reviewing the package in -proposed and the details of this bug report I noticed that the bug description is missing information required for the SRU process. You can find full details at http://wiki.ubuntu.com/StableReleaseUpdates#Procedure but essentially this bug is missing some of the following: a statement of impact, a test case and details regarding where problems may occur. Thanks in advance!

[Brian Murray (brian-murray)]

I find the statement "focal does not have nvidia driver lower than 450" in the bug description confusing. I see the source package nvidia-graphics-drivers-390 as being available in Focal.

https://launchpad.net/ubuntu/+source/nvidia-graphics-drivers-390

Could somebody give some more information about how setting the GPU mode to on-demand will work with this driver?

[jeremyszu (os369510)]

Hi Brian,

Let me think about your case, it's not a fresh installed system since all nvidia drivers are backward compatible. Thus, user will get the newer (e.g. 460 or 470) when installing the new stock ubuntu.

Since the Bug1942307, I will assume the user is staying at "nvidia" mode if user didn't select the nvidia mode manually. (which means the "/etc/prime-discrete" is "on" in the users you worry about)

[Timo Aaltonen (tjaalton)]

But if you have hw that drivers newer than -390 don't support, you're stuck with -390. What would happen on such system?

[jeremyszu (os369510)]

Hi Timo,

For new installation (e.g. 20.04.4) with old GPU, I _think_ (I don't have such hardware) it will switch to on-demand mode (nvidia offload) and won't enable RTD3.

[Dirk Su (dirksu)]

@Brian

I updated the description. Do you think the information in description is enough to continue the SRU process?
And the packages is uploaded to queue.
Focal: https://launchpad.net/ubuntu/focal/+upload/27068997/+files/nvidia-prime_0.8.16~0.20.04.2_source.changes
Hirsute: https://launchpad.net/ubuntu/hirsute/+upload/27068995/+files/nvidia-prime_0.8.16.2~0.21.04.1_source.changes

[Chris Halse Rogers (raof)]

So, I think the next step here is to work out how to answer the question “what happens with -390”, and to commit to *testing* what happens with -390 as a part of the test plan.

[Dirk Su (dirksu)]

With test on Dell Vostro 5568 witch got GPU can be supported by nvidia-driver-390 package. Install nvidia-driver-390 via ubuntu-drivers install nvidia:390. The default GPU mode will be nvidia. Manually switch GPU mode to on-demand, and running glxinfo will get "Error: couldn't find RGB GLX visual or fbconfig". It seems on-demand mode not work with nvidia-driver-390.

[jeremyszu (os369510)]

As comment#10, this SRU introduces a regression[1], I'll propose some packages and asking Alberto to review.

[1] https://bugs.launchpad.net/ubuntu/+source/ubuntu-drivers-common/+bug/1957094

[Dirk Su (dirksu)]

Test plan had been updated to cover the nvidia-driver-390 case.

[jeremyszu (os369510)]

Hi Chris,

For -390, we did find a machine to test it and also provided a corresponding handler in
https://bugs.launchpad.net/ubuntu/+source/ubuntu-drivers-common/+bug/1957094

The bug1957094 is completed, does it solve your concerns?

Also CC, Brian and Timo for awareness.

[Chris Halse Rogers (raof)]

Hello jeremyszu, or anyone else affected,

Accepted nvidia-prime into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/nvidia-prime/0.8.16~0.20.04.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Dirk Su (dirksu)]

Install Focal on Dell notebook Precision 7750 (202004-27817). Enable focal-proposed channel, install nvidia with "sudo ubuntu-drivers install nvidia" then reboot system. Check system is in on-demand with "prime-select query". Check nvidia module parameter with "cat /proc/driver/nvidia/params | grep DynamicPowerManagement" and get result 2 which means GPU enabled with RTD3.

[Dirk Su (dirksu)]

Install Focal on HP EliteOne 800 G6 All-in-One (202008-28167). Enable focal-proposed channel, install nvidia with "sudo ubuntu-drivers install nvidia" then reboot system. Check system is in on-demand with "prime-select query". Since this machine has all-in-one in chassis type, only enabled off-load mode and disabled RTD3.

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for nvidia-prime has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package nvidia-prime - 0.8.16~0.20.04.2

---------------
nvidia-prime (0.8.16~0.20.04.2) focal; urgency=medium

  [ Jeremy Szu ]
  * Set on-demand mode as default nvidia mode (LP: #1942307)

  [ Alberto Milone ]
  * prime-select:
    - Detect chassis type and enable RTD3 only
      on laptops (LP: #1942788).
    - on-demand mode doesn't need to depend on
      RTD3 (LP: #1942789).
    - Don't check the current profile when setting
      a profile (LP: #1946476).
    - Handle BrokenPipeError (LP: #1965520).

 -- Alberto Milone <email address hidden> Thu, 28 Oct 2021 16:40:04 +0200