serial: stm32: fix probe and remove order

Fix probe and remove order to register the port at the end of the probe and
to unregister the port at the beginning of the remove. This enforce
resource allocation and free occur at proper time.

Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Change-Id: I219cad0a31238404b84a79eab4eaaecd65fa04b4
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/155492
Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>
Reviewed-by: Fabrice GASNIER <fabrice.gasnier@st.com>

Author: Erwan Le Ray

drivers/tty/serial/stm32-usart.c

@@ -1313,10 +1313,6 @@ static int stm32_serial_probe(struct platform_device *pdev)
 		device_set_wakeup_enable(&pdev->dev, false);
 	}
 
-	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
-	if (ret)
-		goto err_wirq;
-
 	ret = stm32_of_dma_rx_probe(stm32port, pdev);
 	if (ret)
 		dev_info(&pdev->dev, "interrupt mode used for rx (no dma)\n");
@@ -1327,14 +1323,38 @@ static int stm32_serial_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, &stm32port->port);
 
+	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
+	if (ret)
+		goto err_dma;
+
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 
 	return 0;
 
-err_wirq:
+err_dma:
+	if (stm32port->rx_ch) {
+		dmaengine_terminate_async(stm32port->rx_ch);
+		dma_release_channel(stm32port->rx_ch);
+	}
+
+	if (stm32port->rx_dma_buf)
+		dma_free_coherent(&pdev->dev,
+				  RX_BUF_L, stm32port->rx_buf,
+				  stm32port->rx_dma_buf);
+
+	if (stm32port->tx_ch) {
+		dmaengine_terminate_async(stm32port->tx_ch);
+		dma_release_channel(stm32port->tx_ch);
+	}
+
+	if (stm32port->tx_dma_buf)
+		dma_free_coherent(&pdev->dev,
+				  TX_BUF_L, stm32port->tx_buf,
+				  stm32port->tx_dma_buf);
+
 	if (stm32port->wakeirq > 0)
 		dev_pm_clear_wake_irq(&pdev->dev);
 
@@ -1358,6 +1378,8 @@ static int stm32_serial_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
+	err = uart_remove_one_port(&stm32_usart_driver, port);
+
 	stm32_clr_bits(port, ofs->cr1, USART_CR1_PEIE);
 	cr3 = readl_relaxed(port->membase + ofs->cr3);
 	cr3 &= ~USART_CR3_EIE;
@@ -1394,8 +1416,6 @@ static int stm32_serial_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(stm32_port->clk);
 
-	err = uart_remove_one_port(&stm32_usart_driver, port);
-
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);