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[1/5] drm/omap: return error if dma_alloc_writecombine fails

Message ID 1434622239-15629-2-git-send-email-tomi.valkeinen@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tomi Valkeinen June 18, 2015, 10:10 a.m. UTC
On a platform with no TILER (e.g. omap3, am43xx), when the user wants to
allocate buffer with flag OMAP_BO_SCANOUT, the buffer needs to be
allocated with dma_alloc_writecombine. For some reason the driver does
not return an error if that alloc fails, instead it continues without
backing memory. This leads to errors later when the user tries to use
the buffer.

This patch makes the driver return an error if dma_alloc_writecombine
fails.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
 drivers/gpu/drm/omapdrm/omap_gem.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Laurent Pinchart June 18, 2015, 2:27 p.m. UTC | #1
Hi Tomi,

Thank you for the patch.

On Thursday 18 June 2015 13:10:35 Tomi Valkeinen wrote:
> On a platform with no TILER (e.g. omap3, am43xx), when the user wants to
> allocate buffer with flag OMAP_BO_SCANOUT, the buffer needs to be
> allocated with dma_alloc_writecombine. For some reason the driver does
> not return an error if that alloc fails, instead it continues without
> backing memory. This leads to errors later when the user tries to use
> the buffer.
> 
> This patch makes the driver return an error if dma_alloc_writecombine
> fails.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
>  drivers/gpu/drm/omapdrm/omap_gem.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c
> b/drivers/gpu/drm/omapdrm/omap_gem.c index 2ab77801cf5f..51c5635aff62
> 100644
> --- a/drivers/gpu/drm/omapdrm/omap_gem.c
> +++ b/drivers/gpu/drm/omapdrm/omap_gem.c
> @@ -1392,9 +1392,17 @@ struct drm_gem_object *omap_gem_new(struct drm_device
> *dev, */
>  		omap_obj->vaddr =  dma_alloc_writecombine(dev->dev, size,
>  				&omap_obj->paddr, GFP_KERNEL);
> -		if (omap_obj->vaddr)
> -			flags |= OMAP_BO_DMA;
> +		if (!omap_obj->vaddr) {
> +			spin_lock(&priv->list_lock);
> +			list_del(&omap_obj->mm_list);
> +			spin_unlock(&priv->list_lock);

Wouldn't it be simpler to move the list_add after the "if ((flags & 
OMAP_BO_SCANOUT) && !priv->has_dmm)" block ? You could then avoid the 
list_del.

> +			kfree(omap_obj);
> +
> +			return NULL;
> +		}
> +
> +		flags |= OMAP_BO_DMA;
>  	}
> 
>  	omap_obj->flags = flags;
diff mbox

Patch

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index 2ab77801cf5f..51c5635aff62 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -1392,9 +1392,17 @@  struct drm_gem_object *omap_gem_new(struct drm_device *dev,
 		 */
 		omap_obj->vaddr =  dma_alloc_writecombine(dev->dev, size,
 				&omap_obj->paddr, GFP_KERNEL);
-		if (omap_obj->vaddr)
-			flags |= OMAP_BO_DMA;
+		if (!omap_obj->vaddr) {
+			spin_lock(&priv->list_lock);
+			list_del(&omap_obj->mm_list);
+			spin_unlock(&priv->list_lock);
 
+			kfree(omap_obj);
+
+			return NULL;
+		}
+
+		flags |= OMAP_BO_DMA;
 	}
 
 	omap_obj->flags = flags;