drm/amdgpu: stop blocking for page filp fences

Just register an callback and reschedule the work item if necessary.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 28 insertions, 16 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 588e86c7c5cc..fc995b45fa8f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -761,6 +761,7 @@ struct amdgpu_flip_work {
         struct fence                    *excl;
         unsigned                        shared_count;
         struct fence                    **shared;
+        struct fence_cb                 cb;
 };
 
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 1d6ef1a95e74..edf91593ac87 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -35,24 +35,32 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>
 
-static void amdgpu_flip_wait_fence(struct amdgpu_device *adev,
-                                   struct fence **f)
+static void amdgpu_flip_callback(struct fence *f, struct fence_cb *cb)
 {
-        long r;
+        struct amdgpu_flip_work *work =
+                container_of(cb, struct amdgpu_flip_work, cb);
+        struct amdgpu_device *adev = work->adev;
+        struct amdgpu_crtc *amdgpu_crtc = adev->mode_info.crtcs[work->crtc_id];
 
-        if (*f == NULL)
-                return;
+        fence_put(f);
+        queue_work(amdgpu_crtc->pflip_queue, &work->flip_work);
+}
 
-        r = fence_wait(*f, false);
-        if (r)
-                DRM_ERROR("failed to wait on page flip fence (%ld)!\n", r);
+static bool amdgpu_flip_handle_fence(struct amdgpu_flip_work *work,
+                                     struct fence **f)
+{
+        struct fence *fence= *f;
+
+        if (fence == NULL)
+                return false;
 
-        /* We continue with the page flip even if we failed to wait on
-         * the fence, otherwise the DRM core and userspace will be
-         * confused about which BO the CRTC is scanning out
-         */
-        fence_put(*f);
         *f = NULL;
+
+        if (!fence_add_callback(fence, &work->cb, amdgpu_flip_callback))
+                return true;
+
+        fence_put(*f);
+        return false;
 }
 
 static void amdgpu_flip_work_func(struct work_struct *__work)
@@ -68,9 +76,12 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
         int vpos, hpos, stat, min_udelay;
         struct drm_vblank_crtc *vblank = &crtc->dev->vblank[work->crtc_id];
 
-        amdgpu_flip_wait_fence(adev, &work->excl);
+        if (amdgpu_flip_handle_fence(work, &work->excl))
+                return;
+
         for (i = 0; i < work->shared_count; ++i)
-                amdgpu_flip_wait_fence(adev, &work->shared[i]);
+                if (amdgpu_flip_handle_fence(work, &work->shared[i]))
+                        return;
 
         /* We borrow the event spin lock for protecting flip_status */
         spin_lock_irqsave(&crtc->dev->event_lock, flags);
@@ -234,7 +245,7 @@ int amdgpu_crtc_page_flip(struct drm_crtc *crtc,
         /* update crtc fb */
         crtc->primary->fb = fb;
         spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
-        queue_work(amdgpu_crtc->pflip_queue, &work->flip_work);
+        amdgpu_flip_work_func(&work->flip_work);
         return 0;
 
 vblank_cleanup: