Thanks for working on this, sounds like getting to the bottom of it was quite a ride!
I have some comments/questions. Please don't be scared away from this large comment! I'm coming into this bug with a fresh perspective, and with my SRU hat on, my main concern here is with regressions, since gdm3 is a critical piece of any ubuntu desktop system, nvidia or not. But first, let me define what I think a regression would look like: 1. Inability to login 2. Session suddenly changed to some fallback, because, with the update, the session the user was using before is now crashing 3. Overriding the user's choice regarding the session they selected in previous logins. For example, I have manually opted in to wayland, and now after this update, suddenly I'm on xorg. 4. This one may be debatable, so please do share your thoughts: default session changes for users who have already logged in in the past, but have NOT made an explicit choice about which session they want. For example, they were logging into wayland because that just happened to be the default, everything is working, now after the update, the default for them reverts to xorg. The difference between (4) and (3) is that here the user made no choice, but in (3) they actually made a choice. Now let's go over my comments/questions. These are all up for discussion. If you have an argument of why foo is set to bar instead of something else, go for it. If something is answered by the actual patch, go for it. If some test idea is nonsense, justify it and we go from there. a) Non-nvidia systems The test plan is focusing on the affected hardware. Since gdm3 is a critical component of any ubuntu desktop system, I'd like to see this test plan covering non-nvidia hardware, and nvidia-only hw. The "where things could go wrong" section states: """ 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. """ Please update the test plan to cover this scenario, i.e., nvidia desktops, perhaps also laptops with only nvidia cards if those exist, and non-nvidia hardware. b) comment #8 mentions something about user preference versus default session. What if I have an affected system, but have opted in to use wayland, will this SRU change my choice and revert that to Xorg? Or is the SRU only changing the default session, i.e., for users who have never logged in before, or have never made a choice? Regardless of the answer, this should also be covered in the test plan c) Linked to (b), please make it clear in the SRU description what will be the behavior for: - newly deployed systems with the update in place - upgraded systems for users who have never logged in before - upgraded systems for users who have logged in already, but never made an explicit choice regarding their session - upgraded systems for users who have logged in already, and have made a choice regarding their session And the test plan should match the behavior above. d) nvidia version The "where things could go wrong" section has this sentence: it is expected to do so only for nvidia driver versions < 470. There is nothing else about this version in the bug's description. Please clarify this behavior: what should happen differently across this version barrier? And then also update the test plan to demonstrate that the intention is actually being followed. e) actual impact Besides the unpredictability in which session is used, is there any other impact to systems that are using wayland instead of xorg? I see some in comment #6, and I think this is the most relevant one: 1. External monitors plugged into Nvidia secondary GPUs weren't accelerated for Wayland sessions until recently (https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3304). Xorg was a better user experience in hindsight. Please list that in the bug's impact section. Is there something else that's worth considering? Are we getting bug reports from users who are having crashes or other undesirable behavior in wayland in these systems? ** Changed in: gdm3 (Ubuntu Jammy) Status: Fix Committed => Incomplete ** Changed in: gdm3 (Ubuntu Noble) Status: Fix Committed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to 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 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
