Re: nouveau: failed to initialise sync

[Alistair Popple]

I am also hitting this with upstream. Reverting d02117f8efaa ("drm/ttm: remove 
special handling for non GEM drivers") also fixed it for me.

The change log for that commit reads:

    drm/ttm: remove special handling for non GEM drivers
    
    vmwgfx is the only driver actually using this. Move the handling into
    the driver instead.

I wonder if Nouveau might actually have been using this somehow too?

 - Alistair

On Sunday, 4 July 2021 5:21:29 AM AEST Corentin Labbe wrote:
> Hello
> 
> Since some days on next, nouveau fail to load:
> [    2.754087] nouveau 0000:02:00.0: vgaarb: deactivate vga console
> [    2.761260] Console: switching to colour dummy device 80x25
> [    2.766888] nouveau 0000:02:00.0: NVIDIA MCP77/MCP78 (0aa480a2)
> [    2.783954] nouveau 0000:02:00.0: bios: version 62.77.2a.00.04
> [    2.810122] nouveau 0000:02:00.0: fb: 256 MiB stolen system memory
> [    3.484031] nouveau 0000:02:00.0: DRM: VRAM: 256 MiB
> [    3.488993] nouveau 0000:02:00.0: DRM: GART: 1048576 MiB
> [    3.494308] nouveau 0000:02:00.0: DRM: TMDS table version 2.0
> [    3.500052] nouveau 0000:02:00.0: DRM: DCB version 4.0
> [    3.505192] nouveau 0000:02:00.0: DRM: DCB outp 00: 01000300 0000001e
> [    3.511632] nouveau 0000:02:00.0: DRM: DCB outp 01: 01011332 00020010
> [    3.518074] nouveau 0000:02:00.0: DRM: DCB conn 00: 00000100
> [    3.523728] nouveau 0000:02:00.0: DRM: DCB conn 01: 00001261
> [    3.529455] nouveau 0000:02:00.0: DRM: failed to initialise sync 
subsystem, -28
> [    3.545946] nouveau: probe of 0000:02:00.0 failed with error -28
> 
> I bisected it to:
> git bisect start
> # good: [62fb9874f5da54fdb243003b386128037319b219] Linux 5.13
> git bisect good 62fb9874f5da54fdb243003b386128037319b219
> # bad: [fb0ca446157a86b75502c1636b0d81e642fe6bf1] Add linux-next specific 
files for 20210701
> git bisect bad fb0ca446157a86b75502c1636b0d81e642fe6bf1
> # good: [f63c4fda987a19b1194cc45cb72fd5bf968d9d90] Merge remote-tracking 
branch 'rdma/for-next'
> git bisect good f63c4fda987a19b1194cc45cb72fd5bf968d9d90
> # bad: [49c8769be0b910d4134eba07cae5d9c71b861c4a] Merge remote-tracking 
branch 'drm/drm-next'
> git bisect bad 49c8769be0b910d4134eba07cae5d9c71b861c4a
> # good: [4e3db44a242a4e2afe33b59793898ecbb61d478e] Merge tag 'wireless-
drivers-next-2021-06-25' of git://git.kernel.org/pub/scm/linux/kernel/git/
kvalo/wireless-drivers-next
> git bisect good 4e3db44a242a4e2afe33b59793898ecbb61d478e
> # bad: [5745d647d5563d3e9d32013ad4e5c629acff04d7] Merge tag 'amd-drm-
next-5.14-2021-06-02' of https://gitlab.freedesktop.org/agd5f/linux into drm-
next
> git bisect bad 5745d647d5563d3e9d32013ad4e5c629acff04d7
> # bad: [c99c4d0ca57c978dcc2a2f41ab8449684ea154cc] Merge tag 'amd-drm-
next-5.14-2021-05-19' of https://gitlab.freedesktop.org/agd5f/linux into drm-
next
> git bisect bad c99c4d0ca57c978dcc2a2f41ab8449684ea154cc
> # bad: [ae25ec2fc6c5a9e5767bf1922cd648501d0f914c] Merge tag 'drm-misc-
next-2021-05-17' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
> git bisect bad ae25ec2fc6c5a9e5767bf1922cd648501d0f914c
> # bad: [cac80e71cfb0b00202d743c6e90333c45ba77cc5] drm/vkms: rename cursor to 
plane on ops of planes composition
> git bisect bad cac80e71cfb0b00202d743c6e90333c45ba77cc5
> # good: [178bdba84c5f0ad14de384fc7f15fba0e272919d] drm/ttm/ttm_device: 
Demote kernel-doc abuses
> git bisect good 178bdba84c5f0ad14de384fc7f15fba0e272919d
> # bad: [3f3a6524f6065fd3d130515e012f63eac74d96da] drm/dp: Clarify DP AUX 
registration time
> git bisect bad 3f3a6524f6065fd3d130515e012f63eac74d96da
> # bad: [6dd7efc437611db16d432e0030f72d0c7e890127] drm/gud: cleanup coding 
style a bit
> git bisect bad 6dd7efc437611db16d432e0030f72d0c7e890127
> # bad: [13b29cc3a722c2c0bc9ab9f72f9047d55d08a2f9] drm/mxsfb: Don't select 
DRM_KMS_FB_HELPER
> git bisect bad 13b29cc3a722c2c0bc9ab9f72f9047d55d08a2f9
> # bad: [d02117f8efaa5fbc37437df1ae955a147a2a424a] drm/ttm: remove special 
handling for non GEM drivers
> git bisect bad d02117f8efaa5fbc37437df1ae955a147a2a424a
> # good: [13ea9aa1e7d891e950230e82f1dd2c84e5debcff] drm/ttm: fix error 
handling if no BO can be swapped out v4
> git bisect good 13ea9aa1e7d891e950230e82f1dd2c84e5debcff
> # first bad commit: [d02117f8efaa5fbc37437df1ae955a147a2a424a] drm/ttm: 
remove special handling for non GEM drivers
> 
> Reverting the patch permit to have nouveau works again.
> 
> Regards
> 
>