[Intel-gfx] [PATCH 1/6] drm/i915/dmabuf: Tighten struct_mutex for unmap_dma_buf

[Tvrtko Ursulin]

On 05/04/16 13:57, Chris Wilson wrote:
> We only need the struct_mutex to manipulate the pages_pin_count on the
> object, we do not need to hold our BKL when freeing the exported
> scatterlist.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_gem_dmabuf.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> index 0506016e18e0..b7d46800c49f 100644
> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> @@ -95,14 +95,12 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
>   {
>   	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
>
> -	mutex_lock(&obj->base.dev->struct_mutex);
> -
>   	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
>   	sg_free_table(sg);
>   	kfree(sg);
>
> +	mutex_lock(&obj->base.dev->struct_mutex);
>   	i915_gem_object_unpin_pages(obj);
> -
>   	mutex_unlock(&obj->base.dev->struct_mutex);
>   }
>
>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko