Nouveau - Jul 2018 - [PATCH 0/2] drm/nouveau: Fix panic on nouveau unload.

nevermind, I just hit it today. Will test your patches

On Tue, Jul 17, 2018 at 12:46 PM, Karol Herbst <kherbst at redhat.com>
wrote:
> 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
>>
>> _______________________________________________
>> Nouveau mailing list
>> Nouveau at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/nouveau

On Tue, Jul 17, 2018 at 9:05 AM Karol Herbst <kherbst at redhat.com>
wrote:
>
> nevermind, I just hit it today. Will test your patches
>
> On Tue, Jul 17, 2018 at 12:46 PM, Karol Herbst <kherbst at
redhat.com> wrote:
> > does this also happen with the newest kernel? I was kind of under the
> > impression we already fixed such issues.
> >
I applied those to the linus branch. I did not test against the
skeggsb/nouveau 4.18 branch.
I noticed these new patches by Lyude Paul in the skeggsb/nouveau repo.
I can test on that
branch on Friday when I regain access to the machine.

with your patches I get this in dmesg when removing nouveau:

[  202.510730] ------------[ cut here ]------------
[  202.510731] sysfs group 'power' not found for kobject
'nv_backlight'
[  202.510736] WARNING: CPU: 0 PID: 8156 at fs/sysfs/group.c:235
sysfs_remove_group+0x71/0x80
[  202.510736] Modules linked in: nouveau(-) r8168(O) ttm zram [last
unloaded: nouveau]
[  202.510740] CPU: 0 PID: 8156 Comm: rmmod Tainted: G        W  O
 4.17.6-gentoo #2
[  202.510741] Hardware name: Notebook
P65_P67RGRERA/P65_P67RGRERA, BIOS 1.05.13 01/27/2016
[  202.510742] RIP: 0010:sysfs_remove_group+0x71/0x80
[  202.510743] RSP: 0018:ffffb92305e3fd10 EFLAGS: 00010286
[  202.510744] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
[  202.510745] RDX: 0000000080000001 RSI: ffffffff8225730c RDI: 00000000ffffffff
[  202.510745] RBP: ffffffff820d1320 R08: 0000000000000048 R09: 00000000000003a0
[  202.510746] R10: ffffef72a10e00c0 R11: 0000000000000001 R12: ffffa2378a0a3498
[  202.510746] R13: ffffffffc05bc5d0 R14: ffffa237923a9100 R15: 0000000000000000
[  202.510747] FS:  00007f144ccf7b80(0000) GS:ffffa237b6400000(0000)
knlGS:0000000000000000
[  202.510748] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  202.510748] CR2: 00005596fe880700 CR3: 000000084fc40001 CR4: 00000000003606f0
[  202.510749] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  202.510750] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  202.510750] Call Trace:
[  202.510753]  device_del+0x51/0x350
[  202.510755]  device_unregister+0x9/0x20
[  202.510766]  nouveau_backlight_exit+0x45/0x60 [nouveau]
[  202.510775]  nouveau_display_destroy+0x24/0x70 [nouveau]
[  202.510784]  nouveau_drm_unload+0x66/0xd0 [nouveau]
[  202.510786]  drm_dev_unregister+0x3a/0xe0
[  202.510787]  drm_put_dev+0x22/0x40
[  202.510796]  nouveau_drm_device_remove+0x42/0x70 [nouveau]
[  202.510798]  pci_device_remove+0x36/0xb0
[  202.510800]  device_release_driver_internal+0x155/0x220
[  202.510802]  driver_detach+0x32/0x70
[  202.510803]  bus_remove_driver+0x47/0xa0
[  202.510804]  pci_unregister_driver+0x24/0x90
[  202.510814]  nouveau_drm_exit+0x15/0x4f0 [nouveau]
[  202.510816]  __se_sys_delete_module+0x165/0x230
[  202.510818]  do_syscall_64+0x50/0x160
[  202.510820]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  202.510821] RIP: 0033:0x7f144c417367
[  202.510822] RSP: 002b:00007ffc364f45c8 EFLAGS: 00000202 ORIG_RAX:
00000000000000b0
[  202.510823] RAX: ffffffffffffffda RBX: 00007ffc364f4628 RCX: 00007f144c417367
[  202.510823] RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000560e1c6f27e8
[  202.510824] RBP: 0000560e1c6f2780 R08: 00007ffc364f3531 R09: 0000000000000000
[  202.510824] R10: 00000000000008da R11: 0000000000000202 R12: 00007ffc364f47f0
[  202.510825] R13: 00007ffc364f5d08 R14: 0000560e1c6f1260 R15: 0000560e1c6f2780
[  202.510826] Code: ff 48 89 df 5b 5d 41 5c e9 ed c4 ff ff 48 89 df
e8 c5 c1 ff ff eb cb 49 8b 14 24 48 8b 75 00 48 c7 c7 f0 0d 24 82 e8
7f 44 e4 ff <0f> 0b 5b 5d 41 5c c3 0f 1f 84 00 00 00 00 00 48 85 f6 74
3
1 41
[  202.510845] ---[ end trace acc8d2d94431d002 ]---


On Tue, Jul 17, 2018 at 5:21 PM, Jeffery Miller <jmiller at neverware.com>
wrote:
> On Tue, Jul 17, 2018 at 9:05 AM Karol Herbst <kherbst at redhat.com>
wrote:
>>
>> nevermind, I just hit it today. Will test your patches
>>
>> On Tue, Jul 17, 2018 at 12:46 PM, Karol Herbst <kherbst at
redhat.com> wrote:
>> > does this also happen with the newest kernel? I was kind of under
the
>> > impression we already fixed such issues.
>> >
>
> I applied those to the linus branch. I did not test against the
> skeggsb/nouveau 4.18 branch.
> I noticed these new patches by Lyude Paul in the skeggsb/nouveau repo.
> I can test on that
> branch on Friday when I regain access to the machine.