nouveau bug in linux/6.1.38-2

[Olaf Skibbe]

Dear Maintainers,

Hereby I would like to report an apparent bug in the nouveau driver in
linux/6.1.38-2.

Running a current debian stable on a Dell Latitude E6510 with a
"NVIDIA Corporation GT218M" graphic card, the monitor turns black
after the grub screen. Also switching to a console (Strg-Alt-F2) shows
just a black screen. Access via ssh is possible.

~# uname -r
6.1.0-10-amd64

demesg shows the following error message:

[    3.560153] WARNING: CPU: 0 PID: 176 at drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c:460 nvkm_dp_acquire+0x26a/0x490 [nouveau]
[    3.560287] Modules linked in: sd_mod t10_pi sr_mod crc64_rocksoft cdrom crc64 crc_t10dif crct10dif_generic nouveau(+) ahci libahci mxm_wmi i2c_algo_bit drm_display_helper libata cec rc_core drm_ttm_helper ttm scsi_mod e1000e drm_kms_helper ptp firewire_ohci sdhci_pci cqhci ehci_pci sdhci ehci_hcd firewire_core i2c_i801 crct10dif_pclmul crct10dif_common drm crc32_pclmul crc32c_intel psmouse usbcore mmc_core crc_itu_t pps_core scsi_common i2c_smbus lpc_ich usb_common battery video wmi button
[    3.560322] CPU: 0 PID: 176 Comm: kworker/u16:5 Not tainted 6.1.0-10-amd64 #1  Debian 6.1.38-2
[    3.560325] Hardware name: Dell Inc. Latitude E6510/0N5KHN, BIOS A17 05/12/2017
[    3.560327] Workqueue: nvkm-disp nv50_disp_super [nouveau]
[    3.560433] RIP: 0010:nvkm_dp_acquire+0x26a/0x490 [nouveau]
[    3.560538] Code: 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 0f 85 37 02 00 00 48 83 c4 60 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc <0f> 0b c1 e8 03 41 88 6d 62 44 89 fe 48 89 df 48 69 c0 cf 0d d6 26
[    3.560541] RSP: 0018:ffff9899c048bd60 EFLAGS: 00010246
[    3.560542] RAX: 0000000000041eb0 RBX: ffff88e0209d2600 RCX: 0000000000041eb0
[    3.560544] RDX: ffffffffc079f760 RSI: 0000000000000000 RDI: ffff9899c048bcf0
[    3.560545] RBP: 0000000000000001 R08: ffff9899c048bc64 R09: 0000000000005b76
[    3.560546] R10: 000000000000000d R11: ffff9899c048bde0 R12: 00000000ffffffea
[    3.560548] R13: ffff88e00b39e480 R14: 0000000000044d45 R15: 0000000000000000
[    3.560549] FS:  0000000000000000(0000) GS:ffff88e123c00000(0000) knlGS:0000000000000000
[    3.560551] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.560552] CR2: 00007f57f4e90451 CR3: 0000000181410000 CR4: 00000000000006f0
[    3.560554] Call Trace:
[    3.560558]  <TASK>
[    3.560560]  ? __warn+0x7d/0xc0
[    3.560566]  ? nvkm_dp_acquire+0x26a/0x490 [nouveau]
[    3.560671]  ? report_bug+0xe6/0x170
[    3.560675]  ? handle_bug+0x41/0x70
[    3.560679]  ? exc_invalid_op+0x13/0x60
[    3.560681]  ? asm_exc_invalid_op+0x16/0x20
[    3.560685]  ? init_reset_begun+0x20/0x20 [nouveau]
[    3.560769]  ? nvkm_dp_acquire+0x26a/0x490 [nouveau]
[    3.560888]  nv50_disp_super_2_2+0x70/0x430 [nouveau]
[    3.560997]  nv50_disp_super+0x113/0x210 [nouveau]
[    3.561103]  process_one_work+0x1c7/0x380
[    3.561109]  worker_thread+0x4d/0x380
[    3.561113]  ? rescuer_thread+0x3a0/0x3a0
[    3.561116]  kthread+0xe9/0x110
[    3.561120]  ? kthread_complete_and_exit+0x20/0x20
[    3.561122]  ret_from_fork+0x22/0x30
[    3.561130]  </TASK>

Further information:

$ lspci -v -s $(lspci | grep -i vga | awk '{ print $1 }')
01:00.0 VGA compatible controller: NVIDIA Corporation GT218M [NVS 3100M] (rev a2) (prog-if 00 [VGA controller])
 	Subsystem: Dell Latitude E6510
 	Flags: bus master, fast devsel, latency 0, IRQ 27
 	Memory at e2000000 (32-bit, non-prefetchable) [size=16M]
 	Memory at d0000000 (64-bit, prefetchable) [size=256M]
 	Memory at e0000000 (64-bit, prefetchable) [size=32M]
 	I/O ports at 7000 [size=128]
 	Expansion ROM at 000c0000 [disabled] [size=128K]
 	Capabilities: <access denied>
 	Kernel driver in use: nouveau
 	Kernel modules: nouveau

I reported this bug to debian already, see
https://bugs.debian.org/1042753 for context.

With support (thanks Diederik!) I managed to figure out that the cause
was a regression between upstream kernel version 6.1.27 and 6.1.38.

I build a new 6.1.38 kernel with these commits reverted:

62aecf23f3d1 drm/nouveau: add nv_encoder pointer check for NULL
fb725beca62d drm/nouveau/dp: check for NULL nv_connector->native_mode
90748be0f4f3 drm/nouveau: don't detect DSM for non-NVIDIA device
5a144bad3e75 nouveau: fix client work fence deletion race

With that kernel the graphic works again.

Please inform me if further tests are required.

Cheers,
Olaf