[PATCH] drm/prime: drop reference on imported dma-buf

[Rob Clark]

From: Rob Clark <rob at ti.com>

The GEM handle takes the reference.  If a driver is actually importing a
foreign dmabuf, rather than just re-importing it's own dmabuf, it needs
to do a get_dma_buf().

Signed-off-by: Rob Clark <rob at ti.com>
---
 drivers/gpu/drm/drm_prime.c                |    7 +++++++
 drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |    4 ++++
 drivers/gpu/drm/i915/i915_gem_dmabuf.c     |    4 ++++
 drivers/gpu/drm/nouveau/nouveau_prime.c    |    5 +++++
 drivers/gpu/drm/radeon/radeon_prime.c      |    4 ++++
 drivers/gpu/drm/udl/udl_gem.c              |    4 ++++
 6 files changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 4f80374..088e018 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -185,6 +185,13 @@ int drm_gem_prime_fd_to_handle(struct drm_device *dev,
 	mutex_unlock(&file_priv->prime.lock);
 	drm_gem_object_unreference_unlocked(obj);
 
+	/*
+	 * Drop the ref we obtained w/ dma_buf_get() for the benefit of
+	 * drivers simply re-importing their own dma-buf.. if drivers
+	 * import a foreign dma-buf, they should get_dma_buf().
+	 */
+	dma_buf_put(dma_buf);
+
 	return 0;
 
 fail:
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index f270790..f8ac75b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -190,6 +190,9 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 		}
 	}
 
+	/* since we are attaching, we need to hold a ref */
+	get_dma_buf(dma_buf);
+
 	attach = dma_buf_attach(dma_buf, drm_dev->dev);
 	if (IS_ERR(attach))
 		return ERR_PTR(-EINVAL);
@@ -250,6 +253,7 @@ err_unmap_attach:
 	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 err_buf_detach:
 	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
 	return ERR_PTR(ret);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index cf6bdec..9d2b2eb 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -189,6 +189,9 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 		}
 	}
 
+	/* since we are attaching, we need to hold a ref */
+	get_dma_buf(dma_buf);
+
 	/* need to attach */
 	attach = dma_buf_attach(dma_buf, dev->dev);
 	if (IS_ERR(attach))
@@ -224,5 +227,6 @@ fail_unmap:
 	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
 	return ERR_PTR(ret);
 }
diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c
index 4c82801..fc30886 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -200,6 +200,10 @@ struct drm_gem_object *nouveau_gem_prime_import(struct drm_device *dev,
 			}
 		}
 	}
+
+	/* since we are attaching, we need to hold a ref */
+	get_dma_buf(dma_buf);
+
 	/* need to attach */
 	attach = dma_buf_attach(dma_buf, dev->dev);
 	if (IS_ERR(attach))
@@ -223,6 +227,7 @@ fail_unmap:
 	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
 	return ERR_PTR(ret);
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon_prime.c b/drivers/gpu/drm/radeon/radeon_prime.c
index 28f79ac..073a8d3 100644
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -195,6 +195,9 @@ struct drm_gem_object *radeon_gem_prime_import(struct drm_device *dev,
 		}
 	}
 
+	/* since we are attaching, we need to hold a ref */
+	get_dma_buf(dma_buf);
+
 	/* need to attach */
 	attach = dma_buf_attach(dma_buf, dev->dev);
 	if (IS_ERR(attach))
@@ -218,5 +221,6 @@ fail_unmap:
 	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
 	return ERR_PTR(ret);
 }
diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index 7bd65bd..47f25d5 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -305,6 +305,9 @@ struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
 	struct udl_gem_object *uobj;
 	int ret;
 
+	/* since we are attaching, we need to hold a ref */
+	get_dma_buf(dma_buf);
+
 	/* need to attach */
 	attach = dma_buf_attach(dma_buf, dev->dev);
 	if (IS_ERR(attach))
@@ -329,5 +332,6 @@ fail_unmap:
 	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
 	return ERR_PTR(ret);
 }
-- 
1.7.9.5