On 07/05/2013 06:46 PM, Laurent Pinchart wrote:
> Hi Joonyoung,
>
> Thank you for the patch.
>
> On Friday 05 July 2013 15:32:35 Joonyoung Shim wrote:
>> From drm gem CMA helper, it wasn't fixed dma_buf refcount problem fixed
>> by commit 011c228. This patch solves it.
> Please add a "Cc:stable at vger.kernel.org" here.
OK.
>
>> Signed-off-by: Joonyoung Shim <jy0922.shim at samsung.com>
> Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>
>> ---
>> drivers/gpu/drm/drm_gem_cma_helper.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c
>> b/drivers/gpu/drm/drm_gem_cma_helper.c index ce06397..3f3a12b 100644
>> --- a/drivers/gpu/drm/drm_gem_cma_helper.c
>> +++ b/drivers/gpu/drm/drm_gem_cma_helper.c
>> @@ -554,7 +554,6 @@ struct drm_gem_object *drm_gem_cma_dmabuf_import(struct
>> drm_device *drm, * refcount on gem itself instead of f_count of dmabuf.
>> */
>> drm_gem_object_reference(obj);
>> - dma_buf_put(dma_buf);
>> return obj;
>> }
>> }
>> @@ -573,6 +572,8 @@ struct drm_gem_object *drm_gem_cma_dmabuf_import(struct
>> drm_device *drm, goto error_gem_free;
>> }
>>
>> + get_dma_buf(dma_buf);
>> +
> As a side note, you have probably placed the get_dma_buf() call here to mimic
> the drm_prime.c code, but would there be anything wrong by placing it right
> before returning the GEM object ? The dma_buf_put() call could then be removed
> from the error path.
Yes, i just placed get_dma_buf() call after dma_buf_attach() is called
because "[PATCH] drm: prime: fix refcounting on the dmabuf import error
path" commit does it so.
I'm not sure whether increased reference count of dma_buf needs right
After dma_buf_attach().
>
>> sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
>> if (IS_ERR_OR_NULL(sgt)) {
>> ret = sgt ? PTR_ERR(sgt) : -ENOMEM;
>> @@ -597,6 +598,7 @@ error_buf_unmap:
>> dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
>> error_buf_detach:
>> dma_buf_detach(dma_buf, attach);
>> + dma_buf_put(dma_buf);
>> error_gem_free:
>> drm_gem_cma_free_object(&cma_obj->base);
>> return ERR_PTR(ret);
