drm/msm/sde: get previous inline fbo during atomic check

The intermediate buffer for inline rotation can't be
allocated until the plane's "prepare" callback, but
attempt to acquire a previously allocated intermediate
buffer during the atomic check instead of waiting until
the prepare callback. This holds an extra reference count
on the buffer so that it persists past the end of the
atomic check phase.

CRs-Fixed: 2062021
Change-Id: I28c4a50f3272b41cebcdef05b0aaeabf5dc494b7
Signed-off-by: Clarence Ip <cip@codeaurora.org>
diff --git a/drivers/gpu/drm/msm/sde/sde_plane.c b/drivers/gpu/drm/msm/sde/sde_plane.c
index b295cd0..3eb4518 100644
--- a/drivers/gpu/drm/msm/sde/sde_plane.c
+++ b/drivers/gpu/drm/msm/sde/sde_plane.c
@@ -1623,7 +1623,12 @@
 		attached_pstate = to_sde_plane_state(attached_state);
 		attached_rstate = &attached_pstate->rot;
 
-		if (attached_rstate->rot_hw != rstate->rot_hw)
+		if (attached_state->fb != state->fb)
+			continue;
+
+		if (sde_plane_get_property(pstate, PLANE_PROP_ROTATION) !=
+			sde_plane_get_property(attached_pstate,
+				PLANE_PROP_ROTATION))
 			continue;
 
 		found++;
@@ -1892,6 +1897,46 @@
 }
 
 /**
+ * _sde_plane_rot_get_fb - attempt to get previously allocated fb/fbo
+ *	If an fb/fbo was already created, either from a previous frame or
+ *	from another plane in the current commit cycle, attempt to reuse
+ *	it for this commit cycle as well.
+ * @plane: Pointer to drm plane
+ * @cstate: Pointer to crtc state
+ * @rstate: Pointer to rotator plane state
+ */
+static void _sde_plane_rot_get_fb(struct drm_plane *plane,
+		struct drm_crtc_state *cstate,
+		struct sde_plane_rot_state *rstate)
+{
+	struct sde_kms_fbo *fbo;
+	struct drm_framebuffer *fb;
+
+	if (!plane || !cstate || !rstate)
+		return;
+
+	fbo = sde_crtc_res_get(cstate, SDE_CRTC_RES_ROT_OUT_FBO,
+			(u64) &rstate->rot_hw->base);
+	fb = sde_crtc_res_get(cstate, SDE_CRTC_RES_ROT_OUT_FB,
+			(u64) &rstate->rot_hw->base);
+	if (fb && fbo) {
+		SDE_DEBUG("plane%d.%d get fb/fbo\n", plane->base.id,
+				rstate->sequence_id);
+	} else if (fbo) {
+		sde_crtc_res_put(cstate, SDE_CRTC_RES_ROT_OUT_FBO,
+				(u64) &rstate->rot_hw->base);
+		fbo = NULL;
+	} else if (fb) {
+		sde_crtc_res_put(cstate, SDE_CRTC_RES_ROT_OUT_FB,
+				(u64) &rstate->rot_hw->base);
+		fb = NULL;
+	}
+
+	rstate->out_fbo = fbo;
+	rstate->out_fb = fb;
+}
+
+/**
  * sde_plane_rot_prepare_fb - prepare framebuffer of the new state
  *	for rotator (pre-sspp) stage
  * @plane: Pointer to drm plane
@@ -1927,30 +1972,8 @@
 	sde_plane_rot_calc_cfg(plane, new_state);
 
 	/* check if stream buffer is already attached to rotator */
-	if (sde_plane_enabled(new_state)) {
-		struct sde_kms_fbo *fbo;
-		struct drm_framebuffer *fb;
-
-		fbo = sde_crtc_res_get(cstate, SDE_CRTC_RES_ROT_OUT_FBO,
-				(u64) &new_rstate->rot_hw->base);
-		fb = sde_crtc_res_get(cstate, SDE_CRTC_RES_ROT_OUT_FB,
-				(u64) &new_rstate->rot_hw->base);
-		if (fb && fbo) {
-			SDE_DEBUG("plane%d.%d get fb/fbo\n", plane->base.id,
-					new_rstate->sequence_id);
-		} else if (fbo) {
-			sde_crtc_res_put(cstate, SDE_CRTC_RES_ROT_OUT_FBO,
-					(u64) &new_rstate->rot_hw->base);
-			fbo = NULL;
-		} else if (fb) {
-			sde_crtc_res_put(cstate, SDE_CRTC_RES_ROT_OUT_FB,
-					(u64) &new_rstate->rot_hw->base);
-			fb = NULL;
-		}
-
-		new_rstate->out_fbo = fbo;
-		new_rstate->out_fb = fb;
-	}
+	if (sde_plane_enabled(new_state) && !new_rstate->out_fb)
+		_sde_plane_rot_get_fb(plane, cstate, new_rstate);
 
 	/* release buffer if output format configuration changes */
 	if (new_rstate->out_fb &&
@@ -2199,6 +2222,10 @@
 
 		sde_plane_rot_calc_cfg(plane, state);
 
+		/* attempt to reuse stream buffer if already available */
+		if (sde_plane_enabled(state))
+			_sde_plane_rot_get_fb(plane, cstate, rstate);
+
 		ret = sde_plane_rot_submit_command(plane, state,
 				SDE_HW_ROT_CMD_VALIDATE);