disp: msm: send power_on event in dual display composer kill scenario

On composer kill event, drm lastclose occurs during which suspend
commit gets triggered on primary. If secondary display is stuck in
continuous splash, then we do a early return without triggering
this suspend commit. On composer start, userspace waits for power on
event, but the drm_driver has never entered suspend state, so power
on event is never sent to userspace. This causes HWC deadlock side
effect and the current change triggers null_commit on secondary
display and then issues a suspend commit on both the displays to
avoid this deadlock issue.

Change-Id: I126f43ba3dd2c3bfa83346e8fd4678f35527893d
Signed-off-by: Jayaprakash Madisetty <quic_jmadiset@quicinc.com>
Signed-off-by: Veera Sundaram Sankaran <quic_veeras@quicinc.com>

msm/sde/sde_kms.c

@@ -2542,6 +2542,7 @@ static int sde_kms_set_crtc_for_conn(struct drm_device *dev,
 	}
 
 	crtc_state->active = true;
+	crtc_state->enable = true;
 	ret = drm_atomic_set_crtc_for_connector(conn_state, enc->crtc);
 	if (ret)
 		SDE_ERROR("error %d setting the crtc\n", ret);
@@ -3800,7 +3801,7 @@ static int sde_kms_get_dsc_count(const struct msm_kms *kms,
 	return 0;
 }
 
-static void _sde_kms_null_commit(struct drm_device *dev,
+static int _sde_kms_null_commit(struct drm_device *dev,
 		struct drm_encoder *enc)
 {
 	struct drm_modeset_acquire_ctx ctx;
@@ -3843,6 +3844,8 @@ end:
 
 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);
+
+	return ret;
 }
 
 
@@ -3871,6 +3874,36 @@ void sde_kms_display_early_wakeup(struct drm_device *dev,
 
 	drm_connector_list_iter_end(&conn_iter);
 }
+static int sde_kms_trigger_null_flush(struct msm_kms *kms)
+{
+	struct sde_kms *sde_kms;
+	struct sde_splash_display *splash_display;
+	int i, rc = 0;
+
+	if (!kms) {
+		SDE_ERROR("invalid kms\n");
+		return -EINVAL;
+	}
+
+	sde_kms = to_sde_kms(kms);
+
+	if (!sde_kms->splash_data.num_splash_displays ||
+		sde_kms->dsi_display_count == sde_kms->splash_data.num_splash_displays)
+		return rc;
+
+	for (i = 0; i < MAX_DSI_DISPLAYS; i++) {
+		splash_display = &sde_kms->splash_data.splash_display[i];
+
+		if (splash_display->cont_splash_enabled && splash_display->encoder) {
+			SDE_DEBUG("triggering null commit on enc:%d\n",
+					DRMID(splash_display->encoder));
+			SDE_EVT32(DRMID(splash_display->encoder), SDE_EVTLOG_FUNC_ENTRY);
+			rc = _sde_kms_null_commit(sde_kms->dev, splash_display->encoder);
+		}
+	}
+
+	return rc;
+}
 
 static void _sde_kms_pm_suspend_idle_helper(struct sde_kms *sde_kms,
 	struct device *dev)
@@ -4180,6 +4213,7 @@ static const struct msm_kms_funcs kms_funcs = {
 	.get_address_space_device = _sde_kms_get_address_space_device,
 	.postopen = _sde_kms_post_open,
 	.check_for_splash = sde_kms_check_for_splash,
+	.trigger_null_flush = sde_kms_trigger_null_flush,
 	.get_mixer_count = sde_kms_get_mixer_count,
 	.get_dsc_count = sde_kms_get_dsc_count,
 };