drm: apple: dptx: Wait for completion of dptx_connect.

Makes connects more reliable.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/gpu/drm/apple/dcp.c

@@ -256,6 +256,8 @@ EXPORT_SYMBOL_GPL(dcp_get_connector_type);
 
 static int dcp_dptx_connect(struct apple_dcp *dcp, u32 port)
 {
+	int ret = 0;
+
 	if (!dcp->phy) {
 		dev_warn(dcp->dev, "dcp_dptx_connect: missing phy\n");
 		return -ENODEV;
@@ -264,22 +266,27 @@ static int dcp_dptx_connect(struct apple_dcp *dcp, u32 port)
 	mutex_lock(&dcp->hpd_mutex);
 	if (!dcp->dptxport[port].enabled) {
 		dev_warn(dcp->dev, "dcp_dptx_connect: dptx service for port %d not enabled\n", port);
-		mutex_unlock(&dcp->hpd_mutex);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_unlock;
 	}
 
 	if (dcp->dptxport[port].connected)
-		goto ret;
+		goto out_unlock;
 
+	reinit_completion(&dcp->dptxport[port].linkcfg_completion);
 	dcp->dptxport[port].atcphy = dcp->phy;
 	dptxport_connect(dcp->dptxport[port].service, 0, dcp->dptx_phy, dcp->dptx_die);
 	dptxport_request_display(dcp->dptxport[port].service);
 	dcp->dptxport[port].connected = true;
 
-ret:
 	mutex_unlock(&dcp->hpd_mutex);
-
+	wait_for_completion_timeout(&dcp->dptxport[port].linkcfg_completion,
+				    msecs_to_jiffies(1000));
 	return 0;
+
+out_unlock:
+	mutex_unlock(&dcp->hpd_mutex);
+	return ret;
 }
 
 static int dcp_dptx_disconnect(struct apple_dcp *dcp, u32 port)

drivers/gpu/drm/apple/dptxep.c

@@ -330,8 +330,10 @@ dptxport_call_will_change_link_config(struct apple_epic_service *service)
 static int
 dptxport_call_did_change_link_config(struct apple_epic_service *service)
 {
+	struct dptx_port *dptx = service->cookie;
 	/* assume the link config did change and wait a little bit */
 	mdelay(10);
+	complete(&dptx->linkcfg_completion);
 	return 0;
 }
 
@@ -573,6 +575,8 @@ int dptxep_init(struct apple_dcp *dcp)
 
 	init_completion(&dcp->dptxport[0].enable_completion);
 	init_completion(&dcp->dptxport[1].enable_completion);
+	init_completion(&dcp->dptxport[0].linkcfg_completion);
+	init_completion(&dcp->dptxport[1].linkcfg_completion);
 
 	dcp->dptxep = afk_init(dcp, DPTX_ENDPOINT, dptxep_ops);
 	if (IS_ERR(dcp->dptxep))

drivers/gpu/drm/apple/dptxep.h

@@ -49,6 +49,7 @@ struct apple_epic_service;
 struct dptx_port {
 	bool enabled, connected;
 	struct completion enable_completion;
+	struct completion linkcfg_completion;
 	u32 unit;
 	struct apple_epic_service *service;
 	union phy_configure_opts phy_ops;