** 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.
-
[ Glossary ]
"nvidia" laptop/system/machine/etc...: A computer with at least one
nvidia GPU, running the proprietary driver version 470 or higher.
"affected" laptop/system/machine/etc...: An nvidia hybrid laptop that,
before installing the fix, on the log-in screen presents the options to
log-in to "Ubuntu" and "Ubuntu on Xorg".
"existing user": A unix user that has already logged-in to a desktop
session at least once, regardless of whether they ever changed the log-
in session or not.
"new user": A unix user that has never logged-in to a desktop session,
regardless of whether it was created before or after the update, or
whether it ever logged in to a TTY or not.
-
[ Test-plans overview ]
The expected behaviour after the update is that:
* for nvidia hybrid laptops affected by the bug: both existing and new users
will log-in to Xorg by default;
* for nvidia hybrid laptops unaffected by the bug: the default session for
new users is Xorg, but existing users will keep their previous preference;
* for nvidia desktops: the default session for new users is Xorg, but
existing users will keep their previous preference;
* for all non-nvidia systems: the default session for new users is Wayland,
but existing users will keep their previous preference;
Test Plan A and B verify that on a nvidia hybrid laptop both existing
users and new users log-in to Xorg by default after the update
Test plans C and D verify that on unaffected nvidia systems the user
preference about which session to log-in to is preserved the update.
Test plans E and F verify that on non-nvidia systems the user preference
about which session to log-in to is preserved after the update.
Test plans *not* marked as "Regression" should only be verified on an
affected laptop.
-
[ Test Plan A ]
- 1. Get an affected nvidia hybrid laptop with Ubuntu 22.04 or 24.04
- 2. Before installing the gdm3 update being tested, log-in selecting "Ubuntu"
- 3. Install the gdm3 update being tested
- 4. Reboot
- 5. At the log-in screen, select your username
- 6. Verify that there is a cogwheel icon at the bottom-right of the screen
- 7. Click on the cogwheel icon to open up the menu
- 8. Verify that the selected option is "Ubuntu"
- 9. Verify that the alternative option is "Ubuntu on Wayland"
- 10. Close the menu without changing the selection ("Ubuntu")
- 11. Log-in
- 12. Verify via "Settings -> About" that "Windowing System" is X11
-
+ 1. Get an affected nvidia hybrid laptop with Ubuntu 22.04 or 24.04
+ 2. Before installing the update being tested, reboot to the log-in screen
+ 3. Select your username
+ 4. Click on the cogwheel icon at the bottom-right of the screen
+ 5. Select "Ubuntu"
+ 6. Log-in
+ 7. Now install the gdm3 update being tested
+ 8. Reboot
+ 9. At the log-in screen, select your username
+ 10. Verify that there is a cogwheel icon at the bottom-right of the screen
+ 11. Click on the cogwheel icon to open up the menu
+ 12. Verify that the selected option is "Ubuntu"
+ 13. Verify that the alternative option is "Ubuntu on Wayland"
+ 14. Close the menu without changing the selection ("Ubuntu")
+ 15. Log-in
+ 16. Verify via "Settings -> About" that "Windowing System" is X11
[ Test Plan B ]
1. Get an affected nvidia hybrid laptop with Ubuntu 22.04 or 24.04
2. Install the gdm3 update being tested
3. Create a new a new User on the system
4. Reboot
5. At the log-in screen, select the new User
6. Verify that there is a cogwheel icon at the bottom-right of the screen
7. Click on the cogwheel icon to open up the menu
8. Verify that the selected option is "Ubuntu"
9. Verify that the alternative option is "Ubuntu on Wayland"
10. Close the menu without changing the selection
11. Log-in
12. Verify via "Settings -> About" that "Windowing System" is X11
-
[ Test Plan C - Regression ]
1. Set up a desktop machine with a single nvidia GPU
2. Before installing the update being tested, reboot to the log-in screen
- 3. Click on the cogwheel icon at the bottom-right of the screen
+ 3. Select your username
+ 4. Click on the cogwheel icon at the bottom-right of the screen
5. Select "Ubuntu on Wayland"
6. Log-in
7. Now install the gdm3 update being tested
8. Reboot
9. Select your username
10. Verify that there is a cogwheel icon at the bottom-right of the screen
11. Click on the cogwheel icon to open up the menu
12. Verify that the selected option is "Ubuntu on Wayland"
-
+ 13. Close the menu without changing the selection
+ 14. Log-in
+ 15. Verify via "Settings -> About" that "Windowing System" is Wayland
[ Test Plan D - Regression ]
1. Set up a desktop machine with a single nvidia GPU
2. Before installing the update being tested, reboot to the log-in screen
- 3. Click on the cogwheel icon at the bottom-right of the screen
- 4. Verify that the available options include "Ubuntu" and "Ubuntu on Wayland"
- 5. Select "Ubuntu"
- 6. Log-in
- 7. Now install the gdm3 update being tested
- 8. Reboot
- 9. Select your username
- 10. Verify that there is a cogwheel icon at the bottom-right of the screen
- 11. Click on the cogwheel icon to open up the menu
- 12. Verify that the selected option is "Ubuntu"
- 13. Verify that the alternative option is "Ubuntu on Wayland"
-
+ 3. Select your username
+ 4. Click on the cogwheel icon at the bottom-right of the screen
+ 5. Verify that the available options include "Ubuntu" and "Ubuntu on Wayland"
+ 6. Select "Ubuntu"
+ 7. Log-in
+ 8. Now install the gdm3 update being tested
+ 9. Reboot
+ 10. Select your username
+ 11. Verify that there is a cogwheel icon at the bottom-right of the screen
+ 12. Click on the cogwheel icon to open up the menu
+ 13. Verify that the selected option is "Ubuntu"
+ 14. Verify that the alternative option is "Ubuntu on Wayland"
+ 15. Close the menu without changing the selection
+ 16. Log-in
+ 17. Verify via "Settings -> About" that "Windowing System" is X11
[ Test plan E - Regression ]
1. Set up an Ubuntu system *without* any nvidia GPUs
2. Before installing the update being tested, reboot to the log-in screen
- 3. Click on the cogwheel icon at the bottom-right of the screen
- 4. Verify that the available options include "Ubuntu" and "Ubuntu on Xorg"
- 5. Select "Ubuntu"
- 6. Log-in
- 7. Now install the gdm3 update being tested
- 8. Reboot
- 9. Select your username
- 10. Verify that there is a cogwheel icon at the bottom-right of the screen
- 11. Click on the cogwheel icon to open up the menu
- 12. Verify that the selected option is "Ubuntu"
- 13. Verify that the alternative option is "Ubuntu on Xorg"
-
+ 3. Select your username
+ 4. Click on the cogwheel icon at the bottom-right of the screen
+ 5. Verify that the available options include "Ubuntu" and "Ubuntu on Xorg"
+ 6. Select "Ubuntu"
+ 7. Log-in
+ 8. Now install the gdm3 update being tested
+ 9. Reboot
+ 10. Select your username
+ 11. Verify that there is a cogwheel icon at the bottom-right of the screen
+ 12. Click on the cogwheel icon to open up the menu
+ 13. Verify that the selected option is "Ubuntu"
+ 14. Verify that the alternative option is "Ubuntu on Xorg"
+ 15. Close the menu without changing the selection
+ 16. Log-in
+ 17. Verify via "Settings -> About" that "Windowing System" is Wayland
[ Test plan F - Regression ]
1. Set up an Ubuntu system *without* any nvidia GPUs
2. Before installing the update being tested, reboot to the log-in screen
- 3. Click on the cogwheel icon at the bottom-right of the screen
- 4. Verify that the available options include "Ubuntu" and "Ubuntu on Xorg"
- 5. Select "Ubuntu on Xorg"
- 6. Log-in
- 7. Now install the gdm3 update being tested
- 8. Reboot
- 9. Select your username
+ 3. Select your username
+ 4. Click on the cogwheel icon at the bottom-right of the screen
+ 5. Verify that the available options include "Ubuntu" and "Ubuntu on Xorg"
+ 6. Select "Ubuntu on Xorg"
+ 7. Log-in
+ 8. Now install the gdm3 update being tested
+ 9. Reboot
+ 10. Select your username
10. Verify that there is a cogwheel icon at the bottom-right of the screen
11. Click on the cogwheel icon to open up the menu
12. Verify that the selected option is "Ubuntu on Xorg"
13. Verify that the alternative option is "Ubuntu"
-
+ 14. Close the menu without changing the selection
+ 15. Log-in
+ 16. 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. This is controlled by checking the version of the nvidia
driver: versions 470 or higher should offer opt-in Wayland, while versions
lower than 470 should not offer Wayland at all.
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
To manage notifications about this bug go to:
https://bugs.launchpad.net/oem-priority/+bug/2080498/+subscriptions
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