Re: [RFC PATCH v2 7/9] drm: atomic: factor out common out-fence operations

[Brian Starkey <brian.starkey@arm.com>]

Hi Gustavo,

As Daniel rightly pointed out you would likely be interested in this
patch.

This is on-top of your v5 patch-set, with the bug-fixes I mentioned
before. I haven't dropped the fence_get(), as I figured you're
probably going to rebase your patches on top of the fence_get() in
sync_file_create(), and then I will do the same.

Thanks,
Brian

On Wed, Oct 26, 2016 at 09:55:06AM +0100, Brian Starkey wrote:
>Some parts of setting up the CRTC out-fence can be re-used for
>writeback out-fences. Factor this out into a separate function.
>
>Signed-off-by: Brian Starkey <brian.starkey@arm.com>
>---
> drivers/gpu/drm/drm_atomic.c |   64 +++++++++++++++++++++++++++---------------
> 1 file changed, 42 insertions(+), 22 deletions(-)
>
>diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>index f434f34..3f8fc97 100644
>--- a/drivers/gpu/drm/drm_atomic.c
>+++ b/drivers/gpu/drm/drm_atomic.c
>@@ -1693,37 +1693,46 @@ void drm_atomic_clean_old_fb(struct drm_device *dev,
> }
> EXPORT_SYMBOL(drm_atomic_clean_old_fb);
>
>-static int crtc_setup_out_fence(struct drm_crtc *crtc,
>-				struct drm_crtc_state *crtc_state,
>-				struct drm_out_fence_state *fence_state)
>+static struct fence *get_crtc_fence(struct drm_crtc *crtc,
>+				    struct drm_crtc_state *crtc_state)
> {
> 	struct fence *fence;
>
>-	fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
>-	if (fence_state->fd < 0) {
>-		return fence_state->fd;
>-	}
>-
>-	fence_state->out_fence_ptr = crtc_state->out_fence_ptr;
>-	crtc_state->out_fence_ptr = NULL;
>-
>-	if (put_user(fence_state->fd, fence_state->out_fence_ptr))
>-		return -EFAULT;
>-
> 	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> 	if (!fence)
>-		return -ENOMEM;
>+		return NULL;
>
> 	fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
> 		   crtc->fence_context, ++crtc->fence_seqno);
>
>+	crtc_state->event->base.fence = fence_get(fence);
>+
>+	return fence;
>+}
>+
>+static int setup_out_fence(struct drm_out_fence_state *fence_state,
>+			   u64 __user *out_fence_ptr,
>+			   struct fence *fence)
>+{
>+	int ret;
>+
>+	DRM_DEBUG_ATOMIC("Putting out-fence %p into user ptr: %p\n",
>+			 fence, out_fence_ptr);
>+
>+	fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
>+	if (fence_state->fd < 0)
>+		return fence_state->fd;
>+
>+	ret = put_user(fence_state->fd, out_fence_ptr);
>+	if (ret)
>+		return ret;
>+
>+	fence_state->out_fence_ptr = out_fence_ptr;
>+
> 	fence_state->sync_file = sync_file_create(fence);
>-	if(!fence_state->sync_file) {
>-		fence_put(fence);
>+	if (!fence_state->sync_file)
> 		return -ENOMEM;
>-	}
>
>-	crtc_state->event->base.fence = fence_get(fence);
> 	return 0;
> }
>
>@@ -1896,10 +1905,21 @@ retry:
> 		}
>
> 		if (crtc_state->out_fence_ptr) {
>-			ret = crtc_setup_out_fence(crtc, crtc_state,
>-						   &fence_state[fence_idx++]);
>-			if (ret)
>+			struct fence *fence = get_crtc_fence(crtc, crtc_state);
>+			if (!fence) {
>+				ret = -ENOMEM;
>+				goto out;
>+			}
>+
>+			ret = setup_out_fence(&fence_state[fence_idx++],
>+					      crtc_state->out_fence_ptr,
>+					      fence);
>+			if (ret) {
>+				fence_put(fence);
> 				goto out;
>+			}
>+
>+			crtc_state->out_fence_ptr = NULL;
> 		}
> 	}
>
>-- 
>1.7.9.5
>