Hi,
On 30-09-16 17:33, Laszlo Ersek wrote:
On 09/30/16 16:59, Hans de Goede wrote:
Hi,
On 30-09-16 16:51, Laszlo Ersek wrote:
On 09/30/16 12:35, Hans de Goede wrote:
Attached are 2 patches against the xserver which should fix this, please give them a try.
Sorry about the delay.
The patches don't seem to fix the issue for me. Please see the Xorg log attached.
I tested the patches as follows. Given that my bisection had been done in a Fedora 24 guest, using
xorg-x11-server-1.18.4-4.fc24 http://koji.fedoraproject.org/koji/buildinfo?buildID=794494
I now rebuilt the guest kernel exactly at the failing commit (a325725 "drm: Lobotomize set_busid nonsense for !pci drivers"), and first reproduced the issue with the above X server.
Then, I ported your patches to "xorg-server-1.18.4" (using the upstream xserver tree), and rebuilt the Fedora package with the backport. For the backport, I had to cherry-pick the following two patches from master first:
1 ca8d88e50310 xfree86: recognize primary BUS_PCI device in xf86IsPrimaryPlatform() 2 ea91db4b8331 config: fix GPUDevice fail when AutoAddGPU off + BusID
This way your patches applied cleanly. (Cherry pick #1 above is actually necessary for semantics, while cherry pick #2 is needed for a clean context only, and has no impact for this test.)
That is, in total, I added the following four patches to the Fedora 24 package:
1 xfree86: recognize primary BUS_PCI device in xf86IsPrimaryPlatform() 2 config: fix GPUDevice fail when AutoAddGPU off + BusID 3 xfree86: Make adding unclaimed devices as GPU devices a separate step 4 xfree86: Try harder to find atleast 1 non GPU Screen
You can find the scratch build that I used for testing here:
xorg-x11-server-1.18.4-4.hans_bz1366842_2.fc24 http://koji.fedoraproject.org/koji/taskinfo?taskID=15875087
Another reason I used F24's X server as basis, rather than upstream HEAD, is that Fedora 24 is pretty young, and it's already on kernel 4.7.4, and I believe it will soon move to kernel 4.8, without (necessarily) rebasing its X server package to upstream. IOW the kernel upgrade to 4.8 will break X in Fedora 24 too, and then I expect the Fedora X maintainers would have to cherry pick those two patches as dependencies just the same.
To summarize, the patches don't seem to help. I shall nonetheless thank you for spending your Friday on this!
Hmm, do you have a xorg.conf file lying around somewhere, the message about the xserver not being able to find an entry for screen 0 does not make sense ...
Good catch, I actually had two files under "/etc/X11/xorg.conf.d/":
- "00-keyboard.conf", from package "systemd-229-13.fc24.x86_64", with
contents
# Read and parsed by systemd-localed. It's probably wise not to edit this file # manually too freely. Section "InputClass" Identifier "system-keyboard" MatchIsKeyboard "on" Option "XkbLayout" "us" EndSection
- "01-resolution.conf", which I had created, in order to set the
preferred display resolution:
Section "Screen" Identifier "Default Screen" Device "Default Device" Monitor "Default Monitor" EndSection
Section "Device" Identifier "Default Device" Driver "modesetting" EndSection
Section "Monitor" Identifier "Default Monitor" Option "PreferredMode" "640x480" # Option "PreferredMode" "1440x900" EndSection
I removed these files now, and repeated the test. Again, the X server wouldn't start, but I think the log file looks a bit different now. Attached.
Ah, ok so it seems that my initial analysis is wrong, the problem is not a re-occuring of the device getting identified as a GPU screen, libdrm sorta depends on bus-ids and the lack of one is causing the server to misbehave. I guess that even with a xorg.conf things will fail with the troublesome kernel version (might be worth trying).
Emil's analysis seems to be spot on. This does not seem easily fixable in userspace / does seem like a real regression as it even breaks things when specifying the device through xorg.conf (I or so I believe) which is something which uses to work ...
I made the mistake of thinking the kernel change was re-triggering the old problem Laszlo fixed, but that does not seem to be the case.
Regards,
Hans