serial: lantiq: store and compare return status correctly

platform_get_irq() returns signed status. It should be stored and
compared as signed value before storing to unsigned variable. Implicit
conversion from signed to unsigned and then comparison with less than
zero is wrong as unsigned value can never be less than zero.

Fixes: f087f01ca2c5 ("serial: lantiq: Use platform_get_irq() to get the interrupt")
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/YcIf7+oSWWn34ND6@debian-BULLSEYE-live-builder-AMD64
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index bb059418cb8241182104cba85ae7bbdcd77199e2..3e324d3f0a6df340f02db7124921b56c7bbaf582 100644 (file)
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -727,16 +727,20 @@ static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
 {
        struct uart_port *port = &ltq_port->port;
        struct platform_device *pdev = to_platform_device(dev);
-
-       ltq_port->tx_irq = platform_get_irq(pdev, 0);
-       if (ltq_port->tx_irq < 0)
-               return ltq_port->tx_irq;
-       ltq_port->rx_irq = platform_get_irq(pdev, 1);
-       if (ltq_port->rx_irq < 0)
-               return ltq_port->rx_irq;
-       ltq_port->err_irq = platform_get_irq(pdev, 2);
-       if (ltq_port->err_irq < 0)
-               return ltq_port->err_irq;
+       int irq;
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0)
+               return irq;
+       ltq_port->tx_irq = irq;
+       irq = platform_get_irq(pdev, 1);
+       if (irq < 0)
+               return irq;
+       ltq_port->rx_irq = irq;
+       irq = platform_get_irq(pdev, 2);
+       if (irq < 0)
+               return irq;
+       ltq_port->err_irq = irq;
 
        port->irq = ltq_port->tx_irq;