Nouveau - Jun 2021 - [PATCH 2/3] drm/radeon: wait for moving fence after pinning

We actually need to wait for the moving fence after pinning
the BO to make sure that the pin is completed.

Signed-off-by: Christian K?nig <christian.koenig at amd.com>
CC: stable at kernel.org
---
 drivers/gpu/drm/nouveau/nouveau_prime.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c
b/drivers/gpu/drm/nouveau/nouveau_prime.c
index 347488685f74..591738545eba 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -93,7 +93,13 @@ int nouveau_gem_prime_pin(struct drm_gem_object *obj)
 	if (ret)
 		return -EINVAL;
 
-	return 0;
+	if (nvbo->bo.moving) {
+		ret = dma_fence_wait(nvbo->bo.moving, true);
+		if (ret)
+			nouveau_bo_unpin(nvbo);
+	}
+
+	return ret;
 }
 
 void nouveau_gem_prime_unpin(struct drm_gem_object *obj)
-- 
2.25.1

We actually need to wait for the moving fence after pinning
the BO to make sure that the pin is completed.

Signed-off-by: Christian K?nig <christian.koenig at amd.com>
CC: stable at kernel.org
---
 drivers/gpu/drm/radeon/radeon_prime.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_prime.c
b/drivers/gpu/drm/radeon/radeon_prime.c
index 42a87948e28c..4a90807351e7 100644
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -77,9 +77,19 @@ int radeon_gem_prime_pin(struct drm_gem_object *obj)
 
 	/* pin buffer into GTT */
 	ret = radeon_bo_pin(bo, RADEON_GEM_DOMAIN_GTT, NULL);
-	if (likely(ret == 0))
-		bo->prime_shared_count++;
-
+	if (unlikely(ret))
+		goto error;
+
+	if (bo->tbo.moving) {
+		ret = dma_fence_wait(bo->tbo.moving, false);
+		if (unlikely(ret)) {
+			radeon_bo_unpin(bo);
+			goto error;
+		}
+	}
+
+	bo->prime_shared_count++;
+error:
 	radeon_bo_unreserve(bo);
 	return ret;
 }
-- 
2.25.1

We actually need to wait for the moving fence after pinning
the BO to make sure that the pin is completed.

Signed-off-by: Christian K?nig <christian.koenig at amd.com>
CC: stable at kernel.org
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index baa980a477d9..37ec59365080 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -214,9 +214,21 @@ static int amdgpu_dma_buf_pin(struct dma_buf_attachment
*attach)
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
+	int r;
 
 	/* pin buffer into GTT */
-	return amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT);
+	r = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT);
+	if (r)
+		return r;
+
+	if (bo->tbo.moving) {
+		r = dma_fence_wait(bo->tbo.moving, true);
+		if (r) {
+			amdgpu_bo_unpin(bo);
+			return r;
+		}
+	}
+	return 0;
 }
 
 /**
-- 
2.25.1

On Mon, Jun 21, 2021 at 03:03:26PM +0200, Christian K?nig
wrote:
> We actually need to wait for the moving fence after pinning
> the BO to make sure that the pin is completed.
> 
> Signed-off-by: Christian K?nig <christian.koenig at amd.com>
> CC: stable at kernel.org
> ---
>  drivers/gpu/drm/nouveau/nouveau_prime.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c
b/drivers/gpu/drm/nouveau/nouveau_prime.c
> index 347488685f74..591738545eba 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_prime.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
> @@ -93,7 +93,13 @@ int nouveau_gem_prime_pin(struct drm_gem_object *obj)
>  	if (ret)
>  		return -EINVAL;
>  
> -	return 0;
> +	if (nvbo->bo.moving) {
Don't we need to hold the dma_resv to read this? We can grab a reference
and then unlock, but I think just unlocked wait can go boom pretty easily
(since we don't hold a reference or lock so someone else can jump in and
free the moving fence).
-Daniel
> +		ret = dma_fence_wait(nvbo->bo.moving, true);
> +		if (ret)
> +			nouveau_bo_unpin(nvbo);
> +	}
> +
> +	return ret;
>  }
>  
>  void nouveau_gem_prime_unpin(struct drm_gem_object *obj)
> -- 
> 2.25.1
> 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch