Hi Ben, Thanks for all those details!
Ben Hutchings <b...@decadent.org.uk> (2023-05-14): > > > > +-------------+-----------------+-----------------+-----------------+ > > | Graphics | Bullseye 11.7 | Bookworm RC 2 | Daily builds | > > +-------------+--------+--------+--------+--------+--------+--------+ > > | | BIOS | UEFI | BIOS | UEFI | BIOS | UEFI | > > +-------------+--------+--------+--------+--------+--------+--------+ > > | | OK | OK | OK | KO-G | OK | KO-G | > > | -vga std | OK | OK | OK | KO-G | OK | KO-G | > > | -vga cirrus | OK | OK | OK | KO-S | OK | KO-S | > > | -vga qxl | OK | OK | OK | OK | OK | OK | > > | -vga virtio | OK | OK | OK | OK | OK | OK | > > | -vga vmware | OK | OK | OK | OK | OK | OK | > > +-------------+--------+--------+--------+--------+--------+--------+ > > I started testing with QEMU and OVMF from unstable, and I'm instead > seeing Xorg failing to start in the same cases you see glitches. The > relevant error message seems to be this one: > http://codesearch.debian.net/show?file=xorg-server_2%3A21.1.7-3%2Fhw%2Fxfree86%2Ffbdevhw%2Ffbdevhw.c&line=504 Checking RC 1, I'm seeing OK results for both `-vga std` (or no options) and `-vga cirrus`. I should note GRUB itself is “text-like” with RC 1, while it's “graphical” with RC 2. Reverting the following commit in debian-installer.git and building a netboot-gtk image against unstable gives me a working graphical installer with `-vga std` (or no options) and `-vga cirrus`. I didn't check the rest of the matrix though. https://salsa.debian.org/installer-team/debian-installer/-/commit/a4dc8c0fe7ad1a0c1506125ad9985f78819a1bb2 So it looks to me the GRUB config fix uncovered a pre-existing bug, and the linux version bump (6.1.20-1 → 6.1.20-2) between RC 1 and RC 2 isn't a factor (xserver-xorg-* udebs didn't change). Interestingly, switching to the bullseye branch and cherry-picking the same GRUB config fix there, and rebuilding d-i against current bullseye, I'm getting exactly the same problem: KO-G for std, KO-S for cirrus! So it looks like this might be a rather old issue, rather than a regression during the Bookworm release cycle. Also, I should note that while my focus was on netboot-gtk mini.iso (because it's much quicker to rebuild/tweak than a netinst image), I'm replicating those results with the netinst images: - Bullseye has a “text-like” GRUB, all good. - Bookworm RC 1 has a “text-like” GRUB, all good. - Bookworm RC 2 has a “graphical” GRUB, issues! > > Questions > > ========= > > > > - Is it really to be expected that X and standard drivers would regress > > this way when moving from Bullseye to Bookworm? > > No. > > > - Or is it expected to require specific kernel modules while that wasn't > > the case before? I've discovered this in VM environments, but maybe > > similar things could be happening on bare metal as well, and maybe > > some more modules should be considered for inclusion? > > No. > > > - Is it acceptable to just bundle bochs, cirrus, and vboxvideo for the > > time being (i.e. RC 3, RC 4, 12.0.0), be it via the nasty approach > > or via a proper linux fb-modules inclusion? > > - Or does shipping those few modules risk breaking the kernel and/or X > > on other platforms? (I'd definitely hope not!) > > I would not expect so. They get used on the installed system, so they > probably work. Copy all! Note for a further session: instead of debugging d-i itself, it should be possible to reproduce those issues in the installed system, by keeping only a specific list of kernel modules and X drivers. Of course, that means having GRUB in “graphical” mode as well (a quick check suggests installing desktop-base, without plymouth*, is sufficient for that part). As a very quick experiment, I tried: - installing xfce4 and desktop-base; - rebooting; - X doesn't start directly, one needs to run startxfce4 from the console. Then: - manually removing all X drivers except fbdev_drv.so; - manually removing both tiny/ drivers (bochs and cirrus); - rebuilding the initramfs; - rebooting. This gives me the following: - std: black screen, not even seeing a console prompt; - cirrus: “garbled/split” screen symptoms in the console, and in X; - qxl: all good in the console and in X. Interestingly, purging desktop-base gets me back to a “text-only” GRUB prompt, but both std and cirrus are exhibiting “garbled/split” screen symptoms in the console and in X. I'll stop here, I just wanted to confirm one could reproduce those issues within the installed system, which should almost always be a debug-friendlier environment than d-i… > > Proposal plan for d-i (Bookworm RC 3, RC 4, and 12.0.0) > > ===================== > > > > Unless I received strong negative feedback before Monday (May 15th), > > I plan on including the nasty approach in RC 3, and to revert it > > altogether in RC 4 if big bad regressions are reported: > > > > https://salsa.debian.org/installer-team/debian-installer/-/commit/9fceca63273d0b501ea64d7b719acafc93a5b7fa > > > > As a side note, keeping the bundling in src:debian-installer for the > > next few weeks makes us autonomous: we can enable and disable those > > extra modules without requiring a new linux upload… so it's nasty but I > > actually thought about the few advantages we were getting out of this! > > > > We should also be OK legal-wise, given we already have linux in > > Built-Using via its udebs, so copying things around from linux-image > > wouldn't change anything there, would it? > > > > Of course in the long run, if having those modules is desired, it will > > be better to have them merged in linux and to drop the nasty code, e.g. > > in a point release. > [...] > > Definitely. > > I will spend some time investigating this, but I doubt I'll come up > with a better fix in time. Thanks so much for your feedback. It'd probably be even less likely to get to the bottom of it (at least as far as I would be able to investigate myself) in a timely manner given the absence of a known good version to use in a bisect session to track down when that “regression” was introduced… Monitoring the ppc64el situation (#1033058) was already on my radar for upcoming point releases, I've added this new issue to the list: https://salsa.debian.org/installer-team/debian-installer/-/issues/3 Maybe I'll end up learning about FB after all… twice the fun! Cheers, -- Cyril Brulebois (k...@debian.org) <https://debamax.com/> D-I release manager -- Release team member -- Freelance Consultant
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