[PATCH 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.w...@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 133ea4728149..ca1bef8fb8dc 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -194,27 +194,28 @@ 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 0dbfd7ad7805..3cb57ea82192 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -66,6 +66,11 @@ 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 ea584b1e5bd2..9787745713df 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
@@ -165,6 +165,9 @@ 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