tty: xuartps: Move request_irq to after setting up the HW

Request_irq() should be _after_ h/w programming, otherwise an
interrupt could be triggered and in-progress before the h/w has been
setup.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index db9e23e..5da1c51 100644 (file)
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -762,13 +762,9 @@ static void cdns_uart_set_termios(struct uart_port *port,
  */
 static int cdns_uart_startup(struct uart_port *port)
 {
+       int ret;
        unsigned long flags;
-       unsigned int retval = 0, status = 0;
-
-       retval = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME,
-                                                               (void *)port);
-       if (retval)
-               return retval;
+       unsigned int status = 0;
 
        spin_lock_irqsave(&port->lock, flags);
 
@@ -814,15 +810,22 @@ static int cdns_uart_startup(struct uart_port *port)
        writel(readl(port->membase + CDNS_UART_ISR_OFFSET),
                        port->membase + CDNS_UART_ISR_OFFSET);
 
+       spin_unlock_irqrestore(&port->lock, flags);
+
+       ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);
+       if (ret) {
+               dev_err(port->dev, "request_irq '%d' failed with %d\n",
+                       port->irq, ret);
+               return ret;
+       }
+
        /* Set the Interrupt Registers with desired interrupts */
        writel(CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_PARITY |
                CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN |
                CDNS_UART_IXR_RXTRIG | CDNS_UART_IXR_TOUT,
                port->membase + CDNS_UART_IER_OFFSET);
 
-       spin_unlock_irqrestore(&port->lock, flags);
-
-       return retval;
+       return 0;
 }
 
 /**