[PATCH] drm/amdgpu: Check entity rq

[Nirmoy]

Hi Xinhui,


Can you please check if you can reproduce the crash with 
https://lists.freedesktop.org/archives/amd-gfx/2020-February/046414.html

Christian fix it earlier, I think he forgot to push it.


Regards,

Nirmoy

On 3/25/20 12:07 PM, xinhui pan wrote:
> gpu recover will call sdma suspend/resume. In this period, ring will be
> disabled. So the vm_pte_scheds(sdma.instance[X].ring.sched)->ready will
> be false.
>
> If we submit any jobs in this ring-disabled period. We fail to pick up
> a rq for vm entity and entity->rq will set to NULL.
> amdgpu_vm_sdma_commit did not check the entity->rq, so fix it. Otherwise
> hit panic.
>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Signed-off-by: xinhui pan <xinhui.pan at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> index cf96c335b258..d30d103e48a2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> @@ -95,6 +95,8 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
>   	int r;
>   
>   	entity = p->direct ? &p->vm->direct : &p->vm->delayed;
> +	if (!entity->rq)
> +		return -ENOENT;
>   	ring = container_of(entity->rq->sched, struct amdgpu_ring, sched);
>   
>   	WARN_ON(ib->length_dw == 0);