[Nouveau] [PATCH 0/2] drm/nouveau: Fix panic on nouveau unload.

[Karol Herbst]

does this also happen with the newest kernel? I was kind of under the
impression we already fixed such issues.

On Thu, Jul 5, 2018 at 9:09 PM, Jeffery Miller <jmiller at neverware.com> wrote:
> If have a couple patches I found while looking at a panic
> I was seeing while unloading the nouveau module.
>
> Unloading the nouveau module on my optimus notebook machine causes
> the system to panic. This started occuring when moving from 4.4
> to 4.14.
>
> These patches make it such that the system does not panic
> when unloading the module.
>
> 4.14 also requires commit 34112bf4935d ("drm/nouveau/fbcon: fix NULL
> pointer access in nouveau_fbcon_destroy") which was already included in
> the 4.18 tree.
>
> These patches make it so I can unload the module without a panic but
> there is a warning when unloading the module:
>  sysfs group 'power' not found for kobject 'nv_backlight'
>  WARNING: CPU: 2 PID: 1434 at fs/sysfs/group.c:235 sysfs_remove_group+0x76/0x80
>  RIP: 0010:sysfs_remove_group+0x76/0x80
>  Call Trace:
>   device_del+0x56/0x350
>   ? down_write+0xe/0x40
>   device_unregister+0x16/0x60
>   nouveau_backlight_exit+0x4a/0x60 [nouveau]
>   nouveau_display_destroy+0x29/0x80 [nouveau]
>   nouveau_drm_unload+0x61/0xd0 [nouveau]
>   drm_dev_unregister+0x3f/0xe0 [drm]
>   drm_put_dev+0x27/0x50 [drm]
>   nouveau_drm_device_remove+0x47/0x70 [nouveau]
>   pci_device_remove+0x3b/0xb0
>   device_release_driver_internal+0x180/0x250
>   driver_detach+0x32/0x5f
>   bus_remove_driver+0x74/0xc6
>   pci_unregister_driver+0x22/0xa0
>   nouveau_drm_exit+0x15/0x16b [nouveau]
>
> I don't beleive them to be related. Perhaps there is another issue here?
>
> Jeffery Miller (2):
>   drm/nouveau/fbcon: Fix NULL pointer access in nouveau_fbcon_destroy.
>   drm/nouveau/bl: Allocate backlight connector nodes.
>
>  drivers/gpu/drm/nouveau/nouveau_backlight.c | 70 ++++++++++++++-------
>  drivers/gpu/drm/nouveau/nouveau_fbcon.c     |  5 +-
>  2 files changed, 51 insertions(+), 24 deletions(-)
>
> --
> 2.17.1
>
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