tty: serial: lpuart: avoid report NULL interrupt

The current driver register irq in .startup() and free the irq in
.shutdown(), then user will see the NULL interrupt output from
'cat /proc/interrupts' after the uart port test completed:
...
 41:        515          0          0          0     GICv3 257 Level     fsl-lpuart
 42:          2          0          0          0     GICv3 258 Level
...

It is better to register all the irqs during probe function via devm_request_irq()
to avoid to call free_irq().

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 849c1f9991cec8e0102719a90fe3325e90f2d72f..f0252184291ed4a3ab49ab03ce634e7be8588bf4 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1276,7 +1276,6 @@ static void rx_dma_timer_init(struct lpuart_port *sport)
 static int lpuart_startup(struct uart_port *port)
 {
        struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
-       int ret;
        unsigned long flags;
        unsigned char temp;
 
@@ -1291,11 +1290,6 @@ static int lpuart_startup(struct uart_port *port)
        sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &
                UARTPFIFO_FIFOSIZE_MASK) + 1);
 
-       ret = devm_request_irq(port->dev, port->irq, lpuart_int, 0,
-                               DRIVER_NAME, sport);
-       if (ret)
-               return ret;
-
        spin_lock_irqsave(&sport->port.lock, flags);
 
        lpuart_setup_watermark(sport);
@@ -1333,7 +1327,6 @@ static int lpuart_startup(struct uart_port *port)
 static int lpuart32_startup(struct uart_port *port)
 {
        struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
-       int ret;
        unsigned long flags;
        unsigned long temp;
 
@@ -1346,11 +1339,6 @@ static int lpuart32_startup(struct uart_port *port)
        sport->rxfifo_size = 0x1 << (((temp >> UARTFIFO_RXSIZE_OFF) &
                UARTFIFO_FIFOSIZE_MASK) - 1);
 
-       ret = devm_request_irq(port->dev, port->irq, lpuart32_int, 0,
-                               DRIVER_NAME, sport);
-       if (ret)
-               return ret;
-
        spin_lock_irqsave(&sport->port.lock, flags);
 
        lpuart32_setup_watermark(sport);
@@ -1380,8 +1368,6 @@ static void lpuart_shutdown(struct uart_port *port)
 
        spin_unlock_irqrestore(&port->lock, flags);
 
-       devm_free_irq(port->dev, port->irq, sport);
-
        if (sport->lpuart_dma_rx_use) {
                del_timer_sync(&sport->lpuart_timer);
                lpuart_dma_rx_free(&sport->port);
@@ -1400,7 +1386,6 @@ static void lpuart_shutdown(struct uart_port *port)
 
 static void lpuart32_shutdown(struct uart_port *port)
 {
-       struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
        unsigned long temp;
        unsigned long flags;
 
@@ -1413,8 +1398,6 @@ static void lpuart32_shutdown(struct uart_port *port)
        lpuart32_write(port, temp, UARTCTRL);
 
        spin_unlock_irqrestore(&port->lock, flags);
-
-       devm_free_irq(port->dev, port->irq, sport);
 }
 
 static void
@@ -2212,16 +2195,22 @@ static int lpuart_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, &sport->port);
 
-       if (lpuart_is_32(sport))
+       if (lpuart_is_32(sport)) {
                lpuart_reg.cons = LPUART32_CONSOLE;
-       else
+               ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0,
+                                       DRIVER_NAME, sport);
+       } else {
                lpuart_reg.cons = LPUART_CONSOLE;
+               ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0,
+                                       DRIVER_NAME, sport);
+       }
+
+       if (ret)
+               goto failed_irq_request;
 
        ret = uart_add_one_port(&lpuart_reg, &sport->port);
-       if (ret) {
-               clk_disable_unprepare(sport->clk);
-               return ret;
-       }
+       if (ret)
+               goto failed_attach_port;
 
        sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
        if (!sport->dma_tx_chan)
@@ -2240,6 +2229,11 @@ static int lpuart_probe(struct platform_device *pdev)
        }
 
        return 0;
+
+failed_attach_port:
+failed_irq_request:
+       clk_disable_unprepare(sport->clk);
+       return ret;
 }
 
 static int lpuart_remove(struct platform_device *pdev)