The gpu-manager should allow RandR offloading without bbswitch

[Alberto Milone]

SRU Request

While bbswitch may fail on some hybrid systems (e.g. on the desktop or when the bbswitch module fails to build), this is not a good reason to prevent the system from offloading rendering to the NVIDIA GPU.

[Impact]
 * This problem makes it impossible to use the NVIDIA GPU on hybrid systems with Intel+NVIDIA GPUs when bbswitch is not available (i.e. when it fails to load).

[Test Case]
 * Make sure to be using a hybrid system with Intel+NVIDIA GPUs.

 * Check that bbswitch is not available. You can do so by posting output of the following command:
   test -e /proc/acpi/bbswitch && echo true || echo false

 * Make sure that the gpu-manager is not disabled (only necessary if you disabled it manually).

 * Install ubuntu-drivers-common from trusty-proposed.

 * Remove all fglrx and nvidia drivers (keep the nvidia-common and the nvidia-prime packages):
   sudo apt-get --purge remove nvidia-331
   sudo apt-get --purge remove nvidia-331
   sudo apt-get --purge remove fglrx
   sudo apt-get --purge remove fglrx-updates

 * Restart the system.

 * Install the nvidia binary driver, reboot, and check that the binary driver is enabled (attach your /var/log/gpu-manager.log)
    - Expected: the NVIDIA discrete GPU is enabled.
    - Bad behavior: the system switches back to the intel driver and the discrete GPU is not used, despite the fact that the system was configured properly.

[Regression Potential]
 * Low. Systems that currently work will keep working as usual, the ones that currently fail should finally work.

[Other Info]
 * N/A

-----------

The gpu-manager should allow RandR offloading without bbswitch. This would allow desktop systems to make use of offloading even when bbswitch is not supported.

Also, nvidia-settings should not complain in such scenarios. See https://bugs.launchpad.net/ubuntu/+source/ubuntu-drivers-common/+bug/1310023/comments/70

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-drivers-common - 1:0.2.98

---------------
ubuntu-drivers-common (1:0.2.98) utopic; urgency=medium

  * gpu-manager.c, gpu-manager.py:
    - Add support for testing core alternatives. This will be needed
      by fglrx.
    - Add the --backup-log parameter. This is only used for debugging
      and disabled by default.
    - Fix a regression that caused the gpu-manager to switch to mesa
      after enabling fglrx on hybrid systems (LP: #1310489). Also
      add a test case so that we don't regress in the future.
    - Check that either fglrx or nvidia is set in xorg.conf when
      xorg.conf is needed.
    - Check if kernel modules are blacklisted before choosing the
      driver (LP: #1310489).
    - Enable only GPUs with open drivers that have connected outputs.
      Attaching to GPUs that have no connected outputs would result
      in a black screen.
    - Allow RandR offloading even without bbswitch (LP: #1349282).
    - Fall back to mesa when failing to enable prime.
    - Do not try to enable prime if the nvidia driver is older than
      331.
    - Do not abort if the settings for prime cannot be found.
      Try creating the file before failing.
    - Avoid false positives of unloaded modules.
    - Use the cleanup attribute.
    - Always use snprintf instead of sprintf.
 -- Alberto Milone <email address hidden> Wed, 27 Aug 2014 10:39:17 +0200

[Brian Murray (brian-murray)]

Hello Alberto, or anyone else affected,

Accepted ubuntu-drivers-common into trusty-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/ubuntu-drivers-common/1:0.2.91.7 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 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, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

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

[Taihsiang Ho (tai271828)]

An I+N machine, Lenovo ThinkPad T440p (CID 201309-14169),
could not reproduce this issue.

However,
I tested this fix by the following steps:

1. install Ubuntu 14.04.1 on Lenovo ThinkPad T440p (CID 201309-14169)
2. sudo apt-get install ubuntu-drivers-common ( to be the latest version 1:0.2.91.6)
3. sudo reboot
4. sudo apt-get install nvidia-331-updates (version: 331.38-0ubuntu7.1)
5. sudo reboot
6. sudo dkms remove bbswitch/0.7 --all
7. reboot
8. /var/log/gpu-manager.log now will tell you 'Is nvidia enabled? no'
9. enabled the proposed pocket via software center
10. sudo apt-get install ubuntu-drivers-common ( to upgrade ubuntu-drivers-common)
11. reboot
12. /var/log/gpu-manager.log now will tell you 'Is nvidia enabled? yes'

--------------------
apt-cache policy ubuntu-drivers-common
The following is the snapshot of the test environment:
ubuntu-drivers-common:
  Installed: 1:0.2.91.7
  Candidate: 1:0.2.91.7
  Version table:
 *** 1:0.2.91.7 0
        500 http://tw.archive.ubuntu.com/ubuntu/ trusty-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     1:0.2.91.6 0
        500 http://tw.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
     1:0.2.91.4 0
        500 http://tw.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

dpkg -l | grep -e nvidia -e bbsw
ii bbswitch-dkms 0.7-2ubuntu1 amd64 Interface for toggling the power on nVidia Optimus video cards
ii nvidia-331-updates 331.38-0ubuntu7.1 amd64 NVIDIA binary driver - version 331.38
ii nvidia-libopencl1-331-updates 331.38-0ubuntu7.1 amd64 NVIDIA OpenCL Driver and ICD Loader library
ii nvidia-opencl-icd-331-updates 331.38-0ubuntu7.1 amd64 NVIDIA OpenCL ICD
ii nvidia-prime 0.6.2 amd64 Tools to enable NVIDIA's Prime
ii nvidia-settings 331.20-0ubuntu8 amd64 Tool for configuring the NVIDIA graphics driver

dkms status
fwts-efi-runtime-dkms, 14.08.00, 3.13.0-36-generic, x86_64: installed
nvidia-331-updates, 331.38, 3.13.0-36-generic, x86_64: installed

lsmod | grep bb (could not found anything)

ubuntu@201309-14169:~$ ls /proc/acpi/
ac_adapter battery button ibm wakeup

[Alberto Milone (albertomilone)]

Taihsiang has shown that, thanks to the new ubuntu-drivers-common, it is now possible to use the nvidia driver in an Optimus system even when bbswitch is not available. This was the point of the SRU.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-drivers-common - 1:0.2.91.7

---------------
ubuntu-drivers-common (1:0.2.91.7) trusty-proposed; urgency=medium

  * gpu-manager.c, gpu-manager.py:
    - Add support for testing core alternatives. This will be needed
      by fglrx.
    - Fix a regression that caused the gpu-manager to switch to mesa
      after enabling fglrx on hybrid systems (LP: #1310489). Also
      add a test case so that we don't regress in the future.
    - Check that either fglrx or nvidia is set in xorg.conf when
      xorg.conf is needed.
    - Check if kernel modules are blacklisted before choosing the
      driver (LP: #1310489).
    - Enable only GPUs with open drivers that have connected outputs.
      Attaching to GPUs that have no connected outputs would result
      in a black screen.
    - Allow RandR offloading even without bbswitch (LP: #1349282).
    - Fall back to mesa when failing to enable prime.
    - Do not try to enable prime if the nvidia driver is older than
      331.
    - Do not abort if the settings for prime cannot be found.
      Try to create the file before failing.
 -- Alberto Milone <email address hidden> Fri, 29 Aug 2014 11:29:55 +0200

[Chris J Arges (arges)]

The verification of the Stable Release Update for ubuntu-drivers-common has completed successfully and the package has now been 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.