[PATCH v4 5/6] drm/komeda: Update writeback signal for side_by_side

[james qian wang (Arm Technology China)]

In side by side mode, a writeback job is completed by two pipelines: left
by master and right by slave, we need to wait both pipeline finished (EOW),
then can signal the writeback job completion.

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang at arm.com>
---
 .../gpu/drm/arm/display/komeda/komeda_crtc.c  | 23 ++++++++++---------
 .../gpu/drm/arm/display/komeda/komeda_kms.h   |  5 ++++
 .../arm/display/komeda/komeda_wb_connector.c  |  3 +++
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 24928b922fbd..78351b7135f8 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -193,27 +193,28 @@ komeda_crtc_unprepare(struct komeda_crtc *kcrtc)
 	return err;
 }
 
-void komeda_crtc_handle_event(struct komeda_crtc   *kcrtc,
+void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
 			      struct komeda_events *evts)
 {
 	struct drm_crtc *crtc = &kcrtc->base;
+	struct komeda_wb_connector *wb_conn = kcrtc->wb_conn;
 	u32 events = evts->pipes[kcrtc->master->id];
 
 	if (events & KOMEDA_EVENT_VSYNC)
 		drm_crtc_handle_vblank(crtc);
 
-	if (events & KOMEDA_EVENT_EOW) {
-		struct komeda_wb_connector *wb_conn = kcrtc->wb_conn;
+	/* handles writeback event */
+	if (events & KOMEDA_EVENT_EOW)
+		wb_conn->complete_pipes |= BIT(kcrtc->master->id);
 
-		if (wb_conn)
-			drm_writeback_signal_completion(&wb_conn->base, 0);
-		else
-			DRM_WARN("CRTC[%d]: EOW happen but no wb_connector.\n",
-				 drm_crtc_index(&kcrtc->base));
+	if (kcrtc->side_by_side &&
+	    (evts->pipes[kcrtc->slave->id] & KOMEDA_EVENT_EOW))
+		wb_conn->complete_pipes |= BIT(kcrtc->slave->id);
+
+	if (wb_conn->expected_pipes == wb_conn->complete_pipes) {
+		wb_conn->complete_pipes = 0;
+		drm_writeback_signal_completion(&wb_conn->base, 0);
 	}
-	/* will handle it together with the write back support */
-	if (events & KOMEDA_EVENT_EOW)
-		DRM_DEBUG("EOW.\n");
 
 	if (events & KOMEDA_EVENT_FLIP) {
 		unsigned long flags;
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index ae6654fe95e2..174fb0a0b49b 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -58,6 +58,11 @@ struct komeda_wb_connector {
 
 	/** @wb_layer: represents associated writeback pipeline of komeda */
 	struct komeda_layer *wb_layer;
+
+	/** @expected_pipes: pipelines are used for the writeback job */
+	u32 expected_pipes;
+	/** @complete_pipes: pipelines which have finished writeback */
+	u32 complete_pipes;
 };
 
 /**
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
index 44e628747654..d6833ea3b822 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
@@ -157,6 +157,9 @@ static int komeda_wb_connector_add(struct komeda_kms_dev *kms,
 		return -ENOMEM;
 
 	kwb_conn->wb_layer = kcrtc->master->wb_layer;
+	kwb_conn->expected_pipes = BIT(kcrtc->master->id);
+	if (kcrtc->side_by_side)
+		kwb_conn->expected_pipes |= BIT(kcrtc->slave->id);
 
 	wb_conn = &kwb_conn->base;
 	wb_conn->encoder.possible_crtcs = BIT(drm_crtc_index(&kcrtc->base));
-- 
2.20.1