** Description changed:

- [Summary]
- On HP ZBook Fury G11 platform preloaded with Ubuntu 22.04. The windowing 
system in "Settings -> About" is Xorg. After doing kernel upgrade from 6.5-oem 
to 6.8-hwe, windowing system become Wayland.
+ [ Impact ]
  
+ On some nvidia hybrid systems, like the HP ZBook Fury G11 platform
+ preloaded with Ubuntu 22.04, the windowing system in "Settings -> About"
+ used to be Xorg but after doing kernel upgrade from 6.5-oem to 6.8-hwe,
+ the windowing system become Wayland.
  
- [Reproduce Steps]
- 1. Update kernel by command "sudo apt install linux-image-oem-22.04d 
linux-modules-nvidia-535-oem-22.04d"
- 2. Reboot system
- 3. After enter desktop, check windowing system via "Settings -> About"
+ There is a race condition in udev rules that makes the default desktop
+ session either Xorg or Wayland depending on the ordering of hardware
+ discovery and modules loading. This would affect both jammy and noble,
+ but being a race condition it is unpredictable which hardware defaults
+ to which desktop session, and the same hardware may behave differently
+ in jammy vs in noble.
  
- [Results]
- Expected: Windowing system remain Xorg
- Actual: Windowing system become Wayland
+ The intended default desktop session was meant to be Wayland, however
+ the vast majority of nvidia hybrid laptops defaulted to Xorg at launch,
+ including and particularly all Ubuntu Certified laptops. For this reason
+ we're considering this a bug and are taking measures to ensure that all
+ nvidia hybrid laptops keep defaulting to Xorg.
+ 
+ The fix removes the udev logic that was trying to make nvidia hybrid
+ laptops specifically prefer Wayland, making that hardware use the same
+ udev rules as nvidia desktops which already default to Xorg.
+ 
+ [ Test Plan ]
+ 
+ 1. Set up a nvidia hybrid laptop with Ubuntu 22.04 or 24.04
+ 2. Install the latest updates, particularly the latest kernel
+ 2. Install the gdm3 update from this bug
+ 3. Create a new a new User on the system
+ 3. Reboot
+ 4. At the log-in screen, select the new User
+ 5. Verify that there is a cogwheel icon at the bottom-right of the screen.
+ 6. Click on the cogwheel icon to open up the menu
+ 7. Verify that the selected option is "Ubuntu"
+ 8. Verify that the alternative option is "Ubuntu on Wayland"
+ 9. Close the menu without changing the selection
+ 10. Log-in
+ 11. Verify via "Settings -> About" that "Windowing System" is X11
+ 
+ [ Where problems could occur ]
+ 
+ The patch only touches the gdm udev rules, only removing some broken udev 
rules that matched specific hardware configurations.
+ At worst, Wayland on nvidia laptops could end up completely hidden away 
rather than opt-in -- it is expected to do so only for nvidia driver versions < 
470.
+ 
+ There should be no regression potential for nvidia desktops or non-
+ nvidia hardware, because such hardware would not have matched the udev
+ rules that are being removed here.

** No longer affects: linux-hwe-6.8 (Ubuntu)

** Also affects: gdm3 (Ubuntu Noble)
   Importance: Undecided
       Status: New

** Also affects: gdm3 (Ubuntu Jammy)
   Importance: Undecided
       Status: New

** Description changed:

  [ Impact ]
  
  On some nvidia hybrid systems, like the HP ZBook Fury G11 platform
  preloaded with Ubuntu 22.04, the windowing system in "Settings -> About"
  used to be Xorg but after doing kernel upgrade from 6.5-oem to 6.8-hwe,
  the windowing system become Wayland.
  
  There is a race condition in udev rules that makes the default desktop
  session either Xorg or Wayland depending on the ordering of hardware
  discovery and modules loading. This would affect both jammy and noble,
  but being a race condition it is unpredictable which hardware defaults
  to which desktop session, and the same hardware may behave differently
  in jammy vs in noble.
  
  The intended default desktop session was meant to be Wayland, however
  the vast majority of nvidia hybrid laptops defaulted to Xorg at launch,
  including and particularly all Ubuntu Certified laptops. For this reason
  we're considering this a bug and are taking measures to ensure that all
  nvidia hybrid laptops keep defaulting to Xorg.
  
  The fix removes the udev logic that was trying to make nvidia hybrid
  laptops specifically prefer Wayland, making that hardware use the same
  udev rules as nvidia desktops which already default to Xorg.
  
  [ Test Plan ]
  
  1. Set up a nvidia hybrid laptop with Ubuntu 22.04 or 24.04
  2. Install the latest updates, particularly the latest kernel
- 2. Install the gdm3 update from this bug
+ 2. Install the gdm3 update being tested
  3. Create a new a new User on the system
  3. Reboot
  4. At the log-in screen, select the new User
  5. Verify that there is a cogwheel icon at the bottom-right of the screen.
  6. Click on the cogwheel icon to open up the menu
  7. Verify that the selected option is "Ubuntu"
  8. Verify that the alternative option is "Ubuntu on Wayland"
  9. Close the menu without changing the selection
  10. Log-in
  11. Verify via "Settings -> About" that "Windowing System" is X11
  
  [ Where problems could occur ]
  
  The patch only touches the gdm udev rules, only removing some broken udev 
rules that matched specific hardware configurations.
  At worst, Wayland on nvidia laptops could end up completely hidden away 
rather than opt-in -- it is expected to do so only for nvidia driver versions < 
470.
  
  There should be no regression potential for nvidia desktops or non-
  nvidia hardware, because such hardware would not have matched the udev
  rules that are being removed here.

-- 
You received this bug notification because you are a member of Ubuntu
Desktop Bugs, which is subscribed to gdm3 in Ubuntu.
https://bugs.launchpad.net/bugs/2080498

Title:
  Default session type changed from Xorg to Wayland in some installs of
  22.04 on Nvidia hybrids since kernel 6.8

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