Nouveau - Jul 2025 - [REGRESSION] NVIDIA ION graphics broken with Linux 6.16-rc*

On 7/9/25 09:16, Jamie Heilman wrote:
> Rui Salvaterra wrote:
>> Hi,
>>
>>
>> The machine (Atom 330 CPU, ION chipset, GeForce 9400M graphics) works,
>> but graphics are dead. Dmesg shows the following (Linux 6.16-rc5):
>>
>> [   34.408331] BUG: kernel NULL pointer dereference, address:
0000000000000000
>> [   34.408351] #PF: supervisor instruction fetch in kernel mode
>> [   34.408358] #PF: error_code(0x0010) - not-present page
>> [   34.408364] PGD 0 P4D 0
>> [   34.408373] Oops: Oops: 0010 [#1] SMP
>> [   34.408383] CPU: 2 UID: 0 PID: 583 Comm: Xorg Not tainted
>> 6.16.0-rc5-dbg+ #187 PREEMPTLAZY
>> [   34.408393] Hardware name: To Be Filled By O.E.M. To Be Filled By
>> O.E.M./To be filled by O.E.M., BIOS 080015  08/13/2009
>> [   34.408399] RIP: 0010:0x0
>> [   34.408414] Code: Unable to access opcode bytes at
0xffffffffffffffd6.
>> [   34.408420] RSP: 0018:ffff88800378bc08 EFLAGS: 00010202
>> [   34.408428] RAX: ffffffff82071c60 RBX: ffff888008e6f000 RCX:
0000000000000978
>> [   34.408434] RDX: 0000000000000020 RSI: 0000000000000002 RDI:
ffff888008e6f000
>> [   34.408440] RBP: ffff88800378bd18 R08: 0000000000000000 R09:
00000000000003ff
>> [   34.408445] R10: 0000000000000000 R11: ffff88800378bcc0 R12:
ffff88800378bdb8
>> [   34.408451] R13: ffff888007dad9c0 R14: ffff888004285680 R15:
ffff888007e671c0
>> [   34.408457] FS:  00007f2cc7b2eb00(0000) GS:ffff888149ecf000(0000)
>> knlGS:0000000000000000
>> [   34.408464] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   34.408469] CR2: ffffffffffffffd6 CR3: 0000000008a08000 CR4:
00000000000006f0
>> [   34.408475] Call Trace:
>> [   34.408482]  <TASK>
>> [   34.408486]  nouveau_gem_ioctl_pushbuf+0x10d8/0x1240
>> [   34.408504]  ? nouveau_gem_ioctl_new+0x160/0x160
>> [   34.408513]  drm_ioctl_kernel+0x7a/0xe0
>> [   34.408524]  drm_ioctl+0x1ef/0x490
>> [   34.408532]  ? nouveau_gem_ioctl_new+0x160/0x160
>> [   34.408541]  ? __handle_mm_fault+0xff2/0x1510
>> [   34.408552]  nouveau_drm_ioctl+0x50/0xa0
>> [   34.408560]  __x64_sys_ioctl+0x4be/0xa90
>> [   34.408570]  ? handle_mm_fault+0xb5/0x1a0
>> [   34.408578]  ? lock_mm_and_find_vma+0x34/0x170
>> [   34.408587]  do_syscall_64+0x51/0x1d0
>> [   34.408596]  entry_SYSCALL_64_after_hwframe+0x4b/0x53
>> [   34.408605] RIP: 0033:0x7f2cc7d2f9dd
>> [   34.408612] Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10
>> c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00
>> 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1a 48 8b 45 c8 64 48 2b 04 25
28 00
>> 00 00
>> [   34.408620] RSP: 002b:00007fff6a501ee0 EFLAGS: 00000246 ORIG_RAX:
>> 0000000000000010
>> [   34.408628] RAX: ffffffffffffffda RBX: 000055c7792b3f78 RCX:
00007f2cc7d2f9dd
>> [   34.408634] RDX: 00007fff6a501fa0 RSI: 00000000c0406481 RDI:
0000000000000011
>> [   34.408640] RBP: 00007fff6a501f30 R08: 0000000000000978 R09:
000055c7792af740
>> [   34.408645] R10: 0000000000000002 R11: 0000000000000246 R12:
00007fff6a501fa0
>> [   34.408651] R13: 00000000c0406481 R14: 0000000000000011 R15:
000055c7792ac700
>> [   34.408660]  </TASK>
>> [   34.408664] Modules linked in:
>> [   34.408671] CR2: 0000000000000000
>> [   34.408678] ---[ end trace 0000000000000000 ]---
>> [   34.408682] RIP: 0010:0x0
>> [   34.408691] Code: Unable to access opcode bytes at
0xffffffffffffffd6.
>> [   34.408696] RSP: 0018:ffff88800378bc08 EFLAGS: 00010202
>> [   34.408703] RAX: ffffffff82071c60 RBX: ffff888008e6f000 RCX:
0000000000000978
>> [   34.408709] RDX: 0000000000000020 RSI: 0000000000000002 RDI:
ffff888008e6f000
>> [   34.408715] RBP: ffff88800378bd18 R08: 0000000000000000 R09:
00000000000003ff
>> [   34.408720] R10: 0000000000000000 R11: ffff88800378bcc0 R12:
ffff88800378bdb8
>> [   34.408726] R13: ffff888007dad9c0 R14: ffff888004285680 R15:
ffff888007e671c0
>> [   34.408731] FS:  00007f2cc7b2eb00(0000) GS:ffff888149ecf000(0000)
>> knlGS:0000000000000000
>> [   34.408738] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   34.408743] CR2: ffffffffffffffd6 CR3: 0000000008a08000 CR4:
00000000000006f0
>> [   34.408750] note: Xorg[583] exited with irqs disabled
>>
>> Unfortunately, bisecting is not feasible for me.
> That looks pretty similar to the problem I posted
> (https://lore.kernel.org/lkml/aElJIo9_Se6tAR1a at audible.transient.net/)
> that I bisected to 862450a85b85 ("drm/nouveau/gf100-: track chan
> progress with non-WFI semaphore release").  It still reverts cleanly
> as of v6.16-rc5 so you might want to give that a shot.
Hi,

Thank you for bisecting!? Are you able to try the attached patch?

Thanks,
Ben.
>
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Hi, Ben,


On Wed, 9 Jul 2025 at 02:15, Ben Skeggs <bskeggs at nvidia.com>
wrote:
>
[snipped]
>
> Thank you for bisecting!  Are you able to try the attached patch?
Thanks a lot, your patch fixes the issue for me! Feel free to add my...

Tested-by: Rui Salvaterra <rsalvaterra at gmail.com>


Kind regards,

Rui