GDM hangs on boot with 5.3rc5 when using wayland

[Troels Liebe Bentsen]

Been testing newer kernels and everything works(5.2.9 works) until 5.3rc series where it seems there is an issue with Wayland and/or the setup on Ubuntu is using, it works on Arch Linux.

When booting with 5.3rc5 GDM hangs on launch showing a blank screen, booting to safe mode trying to start weston results in:
Date: 2019-08-24 CEST
[23:29:54.788] weston 5.0.0
               https://wayland.freedesktop.org
               Bug reports to: https://gitlab.freedesktop.org/wayland/weston/issues/
               Build: unknown (not built from git or tarball)
[23:29:54.788] Command line: /usr/bin/weston
[23:29:54.788] OS: Linux, 5.3.0-050300rc5-generic, #201908182231 SMP Sun Aug 18 22:33:18 UTC 2019, x86_64
[23:29:54.788] Using config file '/home/tlb/.config/weston.ini'
[23:29:54.788] Output repaint window is 7 ms maximum.
[23:29:54.788] Loading module '/usr/lib/x86_64-linux-gnu/libweston-5/drm-backend.so'
[23:29:54.790] initializing drm backend
[23:29:54.792] logind: session control granted
[23:29:54.793] no drm device found
[23:29:54.793] fatal: failed to create compositor backend

I know this is not supported but there are some nice thermal fixes in 5.3 for the Dell XPS 9380 and 9370 that would be nice to have.

How do i debug this?

Regards Troels

[Troels Liebe Bentsen (tlbdk)]

Found out it's unrelated to Wayland or GDM, I was using the "i915.enable_guc=-1" to load the Intel power management firmware, this causes the DRM initialization to fail if the needed version is missing and the firmware was updated in 5.3.

Aug 25 23:32:02 xps9380 kernel: [drm] GuC: Failed to fetch firmware i915/kbl_guc_32.0.3.bin (error -2)
Aug 25 23:32:02 xps9380 kernel: [drm] GuC: Firmware can be downloaded from https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/i915
Aug 25 23:32:02 xps9380 kernel: ath10k_pci 0000:02:00.0: enabling device (0000 -> 0002)
Aug 25 23:32:02 xps9380 kernel: ath10k_pci 0000:02:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 reset_mode 0
Aug 25 23:32:02 xps9380 kernel: ------------[ cut here ]------------
Aug 25 23:32:02 xps9380 kernel: WARNING: CPU: 3 PID: 466 at drivers/gpu/drm/drm_mode_config.c:461 drm_mode_config_cleanup.cold+0x32/0x6e [drm]
Aug 25 23:32:02 xps9380 kernel: Modules linked in: ath10k_pci(+) ath10k_core uvcvideo(+) videobuf2_vmalloc snd_seq_device videobuf2_memops ath videobuf2_v4l2 snd_timer videobuf2_common dell_wmi mac80211 d
Aug 25 23:32:02 xps9380 kernel: CPU: 3 PID: 466 Comm: systemd-udevd Tainted: G U 5.3.0-050300rc5-generic #201908182231
Aug 25 23:32:02 xps9380 kernel: Hardware name: Dell Inc. XPS 13 9380/0KTW76, BIOS 1.5.0 06/03/2019
Aug 25 23:32:02 xps9380 kernel: RIP: 0010:drm_mode_config_cleanup.cold+0x32/0x6e [drm]
Aug 25 23:32:02 xps9380 kernel: Code: 55 1f a6 f3 0f 0b e9 bd 00 ff ff 48 c7 c7 70 d2 6b c0 e8 42 1f a6 f3 0f 0b e9 f6 ff fe ff 48 c7 c7 70 d2 6b c0 e8 2f 1f a6 f3 <0f> 0b 48 8d 75 a8 4c 89 e7 e8 7e 83 fe
Aug 25 23:32:02 xps9380 kernel: RSP: 0018:ffffbb4ec0767910 EFLAGS: 00010246
Aug 25 23:32:02 xps9380 kernel: RAX: 0000000000000024 RBX: ffff98dd166202b0 RCX: 0000000000000000
Aug 25 23:32:02 xps9380 kernel: RDX: 0000000000000000 RSI: ffff98dd1e4d7448 RDI: ffff98dd1e4d7448
Aug 25 23:32:02 xps9380 kernel: RBP: ffffbb4ec0767968 R08: ffff98dd1e4d7448 R09: 0000000000000004
Aug 25 23:32:02 xps9380 kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff98dd16620000
Aug 25 23:32:02 xps9380 kernel: R13: ffff98dd166202b8 R14: 0000000000000000 R15: 00000000fffffff8
Aug 25 23:32:02 xps9380 kernel: FS: 00007f01a93638c0(0000) GS:ffff98dd1e4c0000(0000) knlGS:0000000000000000
Aug 25 23:32:02 xps9380 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug 25 23:32:02 xps9380 kernel: CR2: 00007f5a99912080 CR3: 00000004971f2004 CR4: 00000000003606e0
Aug 25 23:32:02 xps9380 kernel: Call Trace:
Aug 25 23:32:02 xps9380 kernel: ? _cond_resched+0x19/0x30
Aug 25 23:32:02 xps9380 kernel: ? mutex_lock+0x13/0x40
Aug 25 23:32:02 xps9380 kernel: intel_modeset_cleanup+0xd1/0x150 [i915]
Aug 25 23:32:02 xps9380 kernel: i915_driver_load+0x553/0x5d0 [i915]
Aug 25 23:32:02 xps9380 kernel: ? mutex_lock+0x13/0x40
Aug 25 23:32:02 xps9380 kernel: i915_pci_probe+0x5a/0x140 [i915]
Aug 25 23:32:02 xps9380 kernel: local_pci_probe+0x48/0x80
Aug 25 23:32:02 xps9380 kernel: pci_device_probe+0x10f/0x1b0
Aug 25 23:32:02 xps9380 kernel: really_probe+0xfb/0x3a0
Aug 25 23:32:02 xps9380 kernel: driver_probe_device+0x5f/0xe0
Aug 25 23:32:02 xps9380 kernel: devic...

[Troels Liebe Bentsen (tlbdk)]

This bug can be closed, one could argue that the kernel could handle this a bit prettier as the -1 options is setting the firmware loading to auto so a fallback to not loading the firmware would be ok.