[nvidia-prime] Cannot adjust brightness in guest session and results in black screen while changing the resolution

[Tammy Yang]

SRU Request

Systems with Optimus (Intel+NVIDIA GPUs) can have problems with the backlight (private bug #1290694) and when detecting and switching to different resolutions (private bug #1285062). Using the intel driver (with SNA) works better than the current solution (the modesetting driver).

[Impact]
 * Backlight control and resolution changes fail on some Optimus systems.

[Test Case]
 * Select performance mode from the nvidia-settings panel and try to adjust the backlight or to cycle through the available resolutions
    - Expected: the backlight can be adjusted, and changing the resolution works.
    - Bad behavior: the backlight can't be adjusted and changing the resolution can some times result in a black screen.

[Regression Potential]
 * Low, as the intel driver is more feature complete than modesetting.

[Other Info]
 * N/A

--

Running the proprietary nvidia drivers in an Optimus config works (Intel+NVIDIA) can discover two issues:

1. Cannot adjust brightness in the guest session (private bug #1290694)
[Test Case]
 * Switch to guest session and adjust brightness from settings or hotkey or command line
    - Expected: Can adjust the brightness
    - Bad behavior: Cannot adjust brightness

2. Black screen while changing the resolution (private bug #1285062)
but switching to the guest session results in a black screen.
[Test Case]
 * Go to display setting, set rotation to counterclockwise/clockwise/180 degrees and click apply
  - Expected results: Can switch display rotation successfully
  - Actual results: Black screen when switching display rotation

[Tammy Yang (wanchingy)]

Alberto has provided a fix in nvidia-prime to change xorg*.template

from
Driver "modesetting"
to
Driver "intel"

and add

Option "AccelMethod" "UXA"

The modified testing package is attached.
With the update of xorg-server for bug #1322212, this nvidia-prime package can pass all OEM QA tests.

[Tammy Yang (wanchingy)]

The package mentioned in comment #1

[Alberto Milone (albertomilone)]

We are disabling rotations in hybrid mode since it's not really supported (see the pending SRU in LP: #1308515). Also switching to the guest session will work.

What the Intel+UXA combination should fix is issues with the backlight i.e. point 1) that you mentioned. I'm not sure about 2).

[Alberto Milone (albertomilone)]

Also, wouldn't SNA be a better choice (vs UXA)? It seems to solve the issue with resolutions too.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-drivers-common - 1:0.2.96

---------------
ubuntu-drivers-common (1:0.2.96) utopic; urgency=medium

  * gpu-manager.c:
    - Try harder when loading bbswitch (LP: #1310023).
      If loading bbswitch fails try with or without the
      "skip_optimus_dsm=1" option.
    - Switch to intel/SNA for optimus systems (LP: #1326257).
 -- Alberto Milone <email address hidden> Wed, 04 Jun 2014 15:59:24 +0200

[Brian Murray (brian-murray)]

Hello Tammy, 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/1:0.2.91.6 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!

[Kai-Heng Feng (kaihengfeng)]

This package also fixes Bug #1330425, caused by xrandr reporting excessive list of resolution/refresh-rate, which makes wrong res/rate value being picked under mirror mode.

[gerald.yang (gerald-yang-tw)]

This package fixes backlight issue.

[gerald.yang (gerald-yang-tw)]

Tested with ubuntu-drivers-common 1:0.2.91.6 in trusty-proposed, it's fixes the backlight issue.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-drivers-common - 1:0.2.91.6

---------------
ubuntu-drivers-common (1:0.2.91.6) trusty-proposed; urgency=medium

  * UbuntuDrivers/detect.py, debian/tests/system, tests/ubuntu_drivers.py:
    - Do not autoinstall the broadcom driver. The open driver should be a
      better solution now (LP: #1306928), as the binary driver prevents
      a number of systems from using the wireless card.
    - Autoinstall linux-firmware-nonfree. This will help now that we no
      longer autoinstall Broadcom's binary driver.
    - Fix the relevant tests now that linux-firmware-nonfree has replaced
      bcmwl.
  * gpu-manager.c, tests/gpu-manager.py:
    - Ignore CRT displays when using PRIME. This works around systems whose
      BIOS provides a ghost output (LP: #1296020).
    - Check that we don't remove xorg.confs on 1st boot (as per the
      previous SRU).
    - Try harder when loading bbswitch (LP: #1310023). If loading bbswitch
      fails try with or without the "skip_optimus_dsm=1" option. Also, make
      sure that we trim dmi resources or matching will give us false
      positives.
    - Switch to intel/SNA for optimus systems (LP: #1326257).
    - Make sure to unload nvidia-uvm or nvidia won't be
      unloaded.
    - Make sure to walk properly the /dev/dri dir. This
      prevents the program from stopping when, for example
      /dev/dri/card1 is available while /dev/dri/card0 is
      not.
 -- Alberto Milone <email address hidden> Fri, 06 Jun 2014 11:20:28 +0200

[Scott Kitterman (kitterman)]

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.

[madbiologist (me-again)]

The black screen after display rotation could be bug 1410238, which is fixed in Trusty's xserver-xorg-video-intel 2:2.99.910-0ubuntu1.4. This bug is also fixed on Utopic and Vivid.

[Steve Langasek (vorlon)]

The Precise Pangolin has reached end of life, so this bug will not be fixed for that release