[AMD Official Use Only - General]
Hi Christian,
Thanks for your suggestion. I will apply it and send out the v2 patch for review.
Regards,
Bob
-----Original Message-----
From: Koenig, Christian <Christian.Koenig@xxxxxxx>
Sent: Wednesday, May 31, 2023 4:33 PM
To: Zhou, Bob <Bob.Zhou@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Min, Frank <Frank.Min@xxxxxxx>
Cc: Chen, Guchun <Guchun.Chen@xxxxxxx>
Subject: Re: [PATCH] drm/amdgpu: skip force complete fences when ring is uninitialized
Am 31.05.23 um 06:48 schrieb Bob Zhou:
> uvd ring in uvd_v7_0_sw_init only initializes ring in bare metal case,
> so when executing amdgpu_uvd_resume to restore fence seq in SRIOV, a
> null pointer dereference will occur. This patch correct this.
Ah! I was already wondering how this bug reports came to be.
In this case please fix the UVD code to not call
amdgpu_fence_driver_force_completion() in the first place instead of hacking around that in the fence code.
Regards,
Christian.
>
> Fixes: 043f2271e2d0a ("drm/amdgpu: mark force completed fences with
> -ECANCELED")
>
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> Oops: 0000 [#1] PREEMPT SMP PTI
> RIP: 0010:amdgpu_fence_driver_set_error+0x3f/0xc0 [amdgpu] Call Trace:
> <TASK>
> amdgpu_fence_driver_force_completion+0x18/0x50 [amdgpu]
> amdgpu_uvd_resume+0x1b2/0x380 [amdgpu]
> ? amdgpu_ring_init+0x73c/0x820 [amdgpu]
> uvd_v7_0_sw_init+0x358/0x450 [amdgpu]
> amdgpu_device_init.cold+0x198c/0x1fdf [amdgpu]
> ? pci_bus_read_config_byte+0x40/0x80
> ? pci_read_config_byte+0x27/0x50
> amdgpu_driver_load_kms+0x1a/0x160 [amdgpu]
> amdgpu_pci_probe+0x186/0x3c0 [amdgpu]
>
> Signed-off-by: Bob Zhou <bob.zhou@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> index c694b41f6461..d2c5484309a6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> @@ -723,6 +723,8 @@ void amdgpu_fence_driver_set_error(struct amdgpu_ring *ring, int error)
> */
> void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring)
> {
> + if (ring->fence_drv.irq_src)
> + return;
> amdgpu_fence_driver_set_error(ring, -ECANCELED);
> amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
> amdgpu_fence_process(ring);
