[PATCH] dma-buf: fix unintended pin/unpin warnings

[Christian König]

Am 17.05.21 um 16:57 schrieb Daniel Vetter:
> On Mon, May 17, 2021 at 10:09:13AM -0400, Alex Deucher wrote:
>> On Mon, May 17, 2021 at 7:57 AM Christian König
>> <ckoenig.leichtzumerken at gmail.com> wrote:
>>> DMA-buf internal users call the pin/unpin functions without having a
>>> dynamic attachment. Avoid the warning and backtrace in the logs.
>>>
>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>> Bugs: https://gitlab.freedesktop.org/drm/intel/-/issues/3481
>>> Fixes: c545781e1c55 ("dma-buf: doc polish for pin/unpin")
>>> CC: stable at kernel.org
>> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
> Hm this means we're losing the dma_resv_assert_held check, do we have that
> in amdgpu callbacks to make sure we're not accidentally breaking stuff
> later on?

Mhm, well this is just for calling the pin/unpin internally from the 
DMA-buf framework itself.

Need to double check, but I think all those cases either have a 
dma_resv_assert_held() or are locking the reservation themselves before 
calling the function.

But yeah, rather good point.

Christian.

>
> But yeah lgtm, Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>
>>> ---
>>>   drivers/dma-buf/dma-buf.c | 10 +++++-----
>>>   1 file changed, 5 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
>>> index f264b70c383e..eadd1eaa2fb5 100644
>>> --- a/drivers/dma-buf/dma-buf.c
>>> +++ b/drivers/dma-buf/dma-buf.c
>>> @@ -760,7 +760,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
>>>
>>>                  if (dma_buf_is_dynamic(attach->dmabuf)) {
>>>                          dma_resv_lock(attach->dmabuf->resv, NULL);
>>> -                       ret = dma_buf_pin(attach);
>>> +                       ret = dmabuf->ops->pin(attach);
>>>                          if (ret)
>>>                                  goto err_unlock;
>>>                  }
>>> @@ -786,7 +786,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
>>>
>>>   err_unpin:
>>>          if (dma_buf_is_dynamic(attach->dmabuf))
>>> -               dma_buf_unpin(attach);
>>> +               dmabuf->ops->unpin(attach);
>>>
>>>   err_unlock:
>>>          if (dma_buf_is_dynamic(attach->dmabuf))
>>> @@ -843,7 +843,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
>>>                  __unmap_dma_buf(attach, attach->sgt, attach->dir);
>>>
>>>                  if (dma_buf_is_dynamic(attach->dmabuf)) {
>>> -                       dma_buf_unpin(attach);
>>> +                       dmabuf->ops->unpin(attach);
>>>                          dma_resv_unlock(attach->dmabuf->resv);
>>>                  }
>>>          }
>>> @@ -956,7 +956,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
>>>          if (dma_buf_is_dynamic(attach->dmabuf)) {
>>>                  dma_resv_assert_held(attach->dmabuf->resv);
>>>                  if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
>>> -                       r = dma_buf_pin(attach);
>>> +                       r = attach->dmabuf->ops->pin(attach);
>>>                          if (r)
>>>                                  return ERR_PTR(r);
>>>                  }
>>> @@ -968,7 +968,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
>>>
>>>          if (IS_ERR(sg_table) && dma_buf_is_dynamic(attach->dmabuf) &&
>>>               !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY))
>>> -               dma_buf_unpin(attach);
>>> +               attach->dmabuf->ops->unpin(attach);
>>>
>>>          if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) {
>>>                  attach->sgt = sg_table;
>>> --
>>> 2.25.1
>>>