serial: sh-sci: Do not free irqs that have already been freed

Since IRQs might be muxed on some parts, we need to pay attention when we
are freeing them.
Otherwise we get the ugly WARNING "Trying to free already-free IRQ 20".

Fixes: 628c534ae735 ("serial: sh-sci: Improve support for separate TEI and DRI interrupts")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 8df0fd8245203f8b5d77aa6f5f8666830ca47b01..64bbeb7d7e0c727e85fe8999ca56c3f03f5cee9f 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1921,7 +1921,7 @@ out_nomem:
 
 static void sci_free_irq(struct sci_port *port)
 {
-       int i;
+       int i, j;
 
        /*
         * Intentionally in reverse order so we iterate over the muxed
@@ -1937,6 +1937,13 @@ static void sci_free_irq(struct sci_port *port)
                if (unlikely(irq < 0))
                        continue;
 
+               /* Check if already freed (irq was muxed) */
+               for (j = 0; j < i; j++)
+                       if (port->irqs[j] == irq)
+                               j = i + 1;
+               if (j > i)
+                       continue;
+
                free_irq(port->irqs[i], port);
                kfree(port->irqstr[i]);