drm/i915: Drain any pending flips on the fb prior to unpinning

If we have queued a page flip on the current fb and then request a mode
change, wait until the page flip completes before performing the new
request.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

3 files changed, 26 insertions, 20 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 37a44c80efd2..ce8ff8fdc55c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1024,6 +1024,9 @@ int i915_do_wait_request(struct drm_device *dev,
                          uint32_t seqno,
                          bool interruptible,
                          struct intel_ring_buffer *ring);
+int i915_gem_wait_for_pending_flip(struct drm_device *dev,
+                                   struct drm_gem_object **object_list,
+                                   int count);
 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 int i915_gem_object_set_to_gtt_domain(struct drm_gem_object *obj,
                                       int write);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 58baecc821a5..a8ddcd499b3b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3497,7 +3497,7 @@ i915_gem_check_execbuffer (struct drm_i915_gem_execbuffer2 *exec,
         return 0;
 }
 
-static int
+int
 i915_gem_wait_for_pending_flip(struct drm_device *dev,
                                struct drm_gem_object **object_list,
                                int count)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 791374c888da..461bf4879e0a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1564,11 +1564,6 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
         struct drm_device *dev = crtc->dev;
         struct drm_i915_master_private *master_priv;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-        struct intel_framebuffer *intel_fb;
-        struct drm_i915_gem_object *obj_priv;
-        struct drm_gem_object *obj;
-        int pipe = intel_crtc->pipe;
-        int plane = intel_crtc->plane;
         int ret;
 
         /* no fb bound */
@@ -1577,38 +1572,46 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
                 return 0;
         }
 
-        switch (plane) {
+        switch (intel_crtc->plane) {
         case 0:
         case 1:
                 break;
         default:
-                DRM_ERROR("Can't update plane %d in SAREA\n", plane);
                 return -EINVAL;
         }
 
-        intel_fb = to_intel_framebuffer(crtc->fb);
-        obj = intel_fb->obj;
-        obj_priv = to_intel_bo(obj);
-
         mutex_lock(&dev->struct_mutex);
-        ret = intel_pin_and_fence_fb_obj(dev, obj, false);
+        ret = intel_pin_and_fence_fb_obj(dev,
+                                         to_intel_framebuffer(crtc->fb)->obj,
+                                         false);
         if (ret != 0) {
                 mutex_unlock(&dev->struct_mutex);
                 return ret;
         }
 
+        if (old_fb) {
+                struct drm_gem_object *obj = to_intel_framebuffer(old_fb)->obj;
+                struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
+
+                if (atomic_read(&obj_priv->pending_flip)) {
+                        ret = i915_gem_wait_for_pending_flip(dev, &obj, 1);
+                        if (ret) {
+                                i915_gem_object_unpin(to_intel_framebuffer(crtc->fb)->obj);
+                                mutex_unlock(&dev->struct_mutex);
+                                return ret;
+                        }
+                }
+        }
+
         ret = intel_pipe_set_base_atomic(crtc, crtc->fb, x, y);
         if (ret) {
-                i915_gem_object_unpin(obj);
+                i915_gem_object_unpin(to_intel_framebuffer(crtc->fb)->obj);
                 mutex_unlock(&dev->struct_mutex);
                 return ret;
         }
 
-        if (old_fb) {
-                intel_fb = to_intel_framebuffer(old_fb);
-                obj_priv = to_intel_bo(intel_fb->obj);
-                i915_gem_object_unpin(intel_fb->obj);
-        }
+        if (old_fb)
+                i915_gem_object_unpin(to_intel_framebuffer(old_fb)->obj);
 
         mutex_unlock(&dev->struct_mutex);
 
@@ -1619,7 +1622,7 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
         if (!master_priv->sarea_priv)
                 return 0;
 
-        if (pipe) {
+        if (intel_crtc->pipe) {
                 master_priv->sarea_priv->pipeB_x = x;
                 master_priv->sarea_priv->pipeB_y = y;
         } else {