Re: [PATCH] drm/amdgpu: add workarounds for Raven VCN TMZ issue

[Lang Yu <Lang.Yu@amd.com>]

O 03/04/ , Christian König wrote:
> Am 04.03.22 um 10:15 schrieb Lang Yu:
> > It is a hardware issue that VCN can't handle a GTT
> > backing stored TMZ buffer on Raven.
> > 
> > Move such a TMZ buffer to VRAM domain before command
> > submission.
> 
> Please don't touch the CS code with that. What you can do is to implement a
> Raven specific patch_cs_in_place callback in the vcn_v*.c file.
> 
> See amdgpu_uvd_force_into_uvd_segment() how we handle the 256MiB window on
> really old UVD blocks. You just don't need to implement the full parsing of
> the command stream (yet).

Thanks for comments and suggestions. I will have a try.

Regards,
Lang

> Regards,
> Christian.
> 
> > 
> > Signed-off-by: Lang Yu <Lang.Yu@amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 27 ++++++++++++++++++++++++++
> >   1 file changed, 27 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > index af12256e1bd3..66345f2ce6ba 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > @@ -393,6 +393,24 @@ void amdgpu_cs_report_moved_bytes(struct amdgpu_device *adev, u64 num_bytes,
> >   	spin_unlock(&adev->mm_stats.lock);
> >   }
> > +static int raven_vcn_tmz_quirks(struct amdgpu_cs_parser *p, struct amdgpu_bo *bo, uint32_t *domain)
> > +{
> > +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> > +	struct amdgpu_ring *ring = to_amdgpu_ring(p->entity->rq->sched);
> > +
> > +	if ((adev->asic_type == CHIP_RAVEN) &&
> > +	    (bo->flags & AMDGPU_GEM_CREATE_ENCRYPTED) &&
> > +	    (ring->funcs->type == AMDGPU_HW_IP_VCN_DEC ||
> > +	    ring->funcs->type == AMDGPU_HW_IP_VCN_ENC ||
> > +	    ring->funcs->type == AMDGPU_HW_IP_VCN_JPEG)) {
> > +		if (domain)
> > +			*domain = AMDGPU_GEM_DOMAIN_VRAM;
> > +		return 1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >   static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
> >   {
> >   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> > @@ -403,6 +421,7 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
> >   		.resv = bo->tbo.base.resv
> >   	};
> >   	uint32_t domain;
> > +	bool need_retry = 1;
> >   	int r;
> >   	if (bo->tbo.pin_count)
> > @@ -431,6 +450,8 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
> >   		domain = bo->allowed_domains;
> >   	}
> > +	raven_vcn_tmz_quirks(p, bo, &domain);
> > +
> >   retry:
> >   	amdgpu_bo_placement_from_domain(bo, domain);
> >   	r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
> > @@ -442,6 +463,12 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
> >   	if (unlikely(r == -ENOMEM) && domain != bo->allowed_domains) {
> >   		domain = bo->allowed_domains;
> > +		if (raven_vcn_tmz_quirks(p, bo, &domain)) {
> > +			if (need_retry)
> > +				need_retry = 0;
> > +			else
> > +				return r;
> > +		}
> >   		goto retry;
> >   	}
>