drm/bridge: anx7625: Fix null vs IS_ERR() checking in anx7625_register_i2c_dummy_clients

Since i2c_new_client_device() function return error pointers.
The i2c_new_dummy_device() function does not return NULL, It returns error
pointers too. Using IS_ERR() to check the return value to fix this.

Fixes: 8bdfc5da("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211222083350.18514-1-linmq006@gmail.comReviewed-by: Robert Foss <robert.foss@linaro.org>

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -1971,40 +1971,54 @@ static const struct drm_bridge_funcs anx7625_bridge_funcs = {
 static int anx7625_register_i2c_dummy_clients(struct anx7625_data *ctx,
 					      struct i2c_client *client)
 {
+	int err = 0;
+
 	ctx->i2c.tx_p0_client = i2c_new_dummy_device(client->adapter,
 						     TX_P0_ADDR >> 1);
-	if (!ctx->i2c.tx_p0_client)
-		return -ENOMEM;
+	if (IS_ERR(ctx->i2c.tx_p0_client))
+		return PTR_ERR(ctx->i2c.tx_p0_client);
 
 	ctx->i2c.tx_p1_client = i2c_new_dummy_device(client->adapter,
 						     TX_P1_ADDR >> 1);
-	if (!ctx->i2c.tx_p1_client)
+	if (IS_ERR(ctx->i2c.tx_p1_client)) {
+		err = PTR_ERR(ctx->i2c.tx_p1_client);
 		goto free_tx_p0;
+	}
 
 	ctx->i2c.tx_p2_client = i2c_new_dummy_device(client->adapter,
 						     TX_P2_ADDR >> 1);
-	if (!ctx->i2c.tx_p2_client)
+	if (IS_ERR(ctx->i2c.tx_p2_client)) {
+		err = PTR_ERR(ctx->i2c.tx_p2_client);
 		goto free_tx_p1;
+	}
 
 	ctx->i2c.rx_p0_client = i2c_new_dummy_device(client->adapter,
 						     RX_P0_ADDR >> 1);
-	if (!ctx->i2c.rx_p0_client)
+	if (IS_ERR(ctx->i2c.rx_p0_client)) {
+		err = PTR_ERR(ctx->i2c.rx_p0_client);
 		goto free_tx_p2;
+	}
 
 	ctx->i2c.rx_p1_client = i2c_new_dummy_device(client->adapter,
 						     RX_P1_ADDR >> 1);
-	if (!ctx->i2c.rx_p1_client)
+	if (IS_ERR(ctx->i2c.rx_p1_client)) {
+		err = PTR_ERR(ctx->i2c.rx_p1_client);
 		goto free_rx_p0;
+	}
 
 	ctx->i2c.rx_p2_client = i2c_new_dummy_device(client->adapter,
 						     RX_P2_ADDR >> 1);
-	if (!ctx->i2c.rx_p2_client)
+	if (IS_ERR(ctx->i2c.rx_p2_client)) {
+		err = PTR_ERR(ctx->i2c.rx_p2_client);
 		goto free_rx_p1;
+	}
 
 	ctx->i2c.tcpc_client = i2c_new_dummy_device(client->adapter,
 						    TCPC_INTERFACE_ADDR >> 1);
-	if (!ctx->i2c.tcpc_client)
+	if (IS_ERR(ctx->i2c.tcpc_client)) {
+		err = PTR_ERR(ctx->i2c.tcpc_client);
 		goto free_rx_p2;
+	}
 
 	return 0;
 
@@ -2021,7 +2035,7 @@ static int anx7625_register_i2c_dummy_clients(struct anx7625_data *ctx,
 free_tx_p0:
 	i2c_unregister_device(ctx->i2c.tx_p0_client);
 
-	return -ENOMEM;
+	return err;
 }
 
 static void anx7625_unregister_i2c_dummy_clients(struct anx7625_data *ctx)