Software rendering is a better bet if DKMS fails, as nouveau can cause problems when dealing with (partially?) supported GPUs. I introduced that change in bionic, but then I reverted that behaviour, also because it would cause problems to hybrid graphics.
I don't think users relying on something that is broken should hold us back. If anything, the fallback would cause users to file bug reports (about graphics corruption, increased power consumption, etc.) against nvidia, where these would be really nouveau's. On Thu, 16 Aug 2018 at 00:36, Steve Langasek <steve.langa...@canonical.com> wrote: > Bug description says: > > > [Regression Potential] > > Low, as hybrid graphics support does not work correctly, and the changes > only affect > > this use case. > > Dropping the nvidia-fallback service means that any time the nvidia > module has failed to be loaded, including if the nvidia module has > failed to build for any reason, the nouveau module will not be loaded in > its place. This is a behavior change that potentially affects users > other than those with hybrid graphics. Is that a concern? How long has > the existing behavior been there, and what are the chances that users > may be inadvertently relying on the current fallback behavior without > knowing it? > > ** Changed in: nvidia-graphics-drivers-390 (Ubuntu Bionic) > Status: In Progress => Incomplete > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/1778011 > > Title: > SRU: PRIME Power Saving mode draws too much power > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1778011/+subscriptions > > Launchpad-Notification-Type: bug > Launchpad-Bug: distribution=ubuntu; sourcepackage=gdm3; component=main; > status=Fix Released; importance=High; assignee= > alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; > sourcepackage=nvidia-graphics-drivers-390; component=restricted; status=Fix > Released; importance=High; assignee=alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; sourcepackage=nvidia-prime; > component=main; status=Fix Released; importance=High; assignee= > alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; sourcepackage=nvidia-settings; > component=main; status=Fix Released; importance=High; assignee= > alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; sourcepackage=ubuntu-drivers-common; > component=main; status=Fix Released; importance=High; assignee= > alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=bionic; > sourcepackage=gdm3; component=main; status=In Progress; importance=High; > assignee=alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=bionic; > sourcepackage=nvidia-graphics-drivers-390; component=restricted; > status=Incomplete; importance=High; assignee=alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=bionic; > sourcepackage=nvidia-prime; component=main; status=In Progress; > importance=High; assignee=alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=bionic; > sourcepackage=nvidia-settings; component=main; status=In Progress; > importance=High; assignee=alberto.mil...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=bionic; > sourcepackage=ubuntu-drivers-common; component=main; status=In Progress; > importance=High; assignee=alberto.mil...@canonical.com; > Launchpad-Bug-Information-Type: Public > Launchpad-Bug-Private: no > Launchpad-Bug-Security-Vulnerability: no > Launchpad-Bug-Commenters: albertomilone andrebrait cantfind ilvipero > janitor vorlon > Launchpad-Bug-Reporter: Alberto Milone (albertomilone) > Launchpad-Bug-Modifier: Steve Langasek (vorlon) > Launchpad-Message-Rationale: Subscriber > Launchpad-Message-For: albertomilone > -- Alberto Milone -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to nvidia-settings in Ubuntu. https://bugs.launchpad.net/bugs/1778011 Title: SRU: PRIME Power Saving mode draws too much power Status in gdm3 package in Ubuntu: Fix Released Status in nvidia-graphics-drivers-390 package in Ubuntu: Fix Released Status in nvidia-prime package in Ubuntu: Fix Released Status in nvidia-settings package in Ubuntu: Fix Released Status in ubuntu-drivers-common package in Ubuntu: Fix Released Status in gdm3 source package in Bionic: Fix Committed Status in nvidia-graphics-drivers-390 source package in Bionic: Incomplete Status in nvidia-prime source package in Bionic: In Progress Status in nvidia-settings source package in Bionic: In Progress Status in ubuntu-drivers-common source package in Bionic: In Progress Bug description: SRU Request: [Impact] Relying on the nouveau driver and on the vga switcheroo (to get around a change in systemd LP: #1777099) caused increased power consumption, and slowed down the switching process. Furthermore, if the main X/Xwayland session was started by Gdm when the nvidia driver was loaded, the session will keep the nvidia module loaded, and prevent the system from switching off the dGPU. Also, the nouveau driver will be loaded, if nvidia is not, and this can cause problems to unsupported NVIDIA GPUs. The solution involves the following changes: 1) Solving the problem in systemd (LP: #1777099) 2) Adding code in gpu-manager and in nvidia-prime to unload the nvidia modules, and to allow the PCI device to sleep. 3) Making a slight change to the current patch in Gdm, used to call the PRIME scripts before and after a Gdm session (so that gpu-manager gets actually called on log out) 4) Adding code in gpu-manager to kill the main X/Xwayland session on log out, if the session is preventing us from unloading the nvidia driver. A new X/Xwayland session will be created after unload the module. 5) Removing the systemd service that loads nouveau from the nvidia packages. [Test Case] 1) Enable the -proposed repository, and install the new "ubuntu-drivers-common", nvidia drivers, nvidia-prime, and gdm3 2) Make sure the nvidia packages are installed, and enable performance mode (if it is already enabled, call "sudo prime-select intel" first): sudo prime-select nvidia 3) Restart your computer and attach your /var/log/gpu-manager.log. see if the system boots correctly. If unsure, please attach your /var/log /gpu-manager.log and /var/log/Xorg.0.log 4) Select power saving mode: sudo prime-select intel 5) Log out and log back in 6) Check if the nvidia driver is still loaded: lsmod | grep nvidia [Regression Potential] Low, as hybrid graphics support does not work correctly, and the changes only affect this use case. 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