serial: sh-sci: Fix for port types without BRI interrupts.

In doing the evt2irq() + muxed vector conversion for various port types
it became apparent that some of the legacy port types will presently
error out due to the irq requesting logic attempting to acquire the
non-existent BRI IRQ. This adds some sanity checks to the request/free
path to ensure that non-existence of a source in itself is not an error.

This should restore functionality for legacy PORT_SCI ports.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index be31d85a50e370fb788a0260897f38080172d66d..4604153b7954b70288399bb675c373f1e16d2bf3 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1052,9 +1052,17 @@ static int sci_request_irq(struct sci_port *port)
                if (SCIx_IRQ_IS_MUXED(port)) {
                        i = SCIx_MUX_IRQ;
                        irq = up->irq;
-               } else
+               } else {
                        irq = port->cfg->irqs[i];
 
+                       /*
+                        * Certain port types won't support all of the
+                        * available interrupt sources.
+                        */
+                       if (unlikely(!irq))
+                               continue;
+               }
+
                desc = sci_irq_desc + i;
                port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
                                            dev_name(up->dev), desc->desc);
@@ -1094,6 +1102,15 @@ static void sci_free_irq(struct sci_port *port)
         * IRQ first.
         */
        for (i = 0; i < SCIx_NR_IRQS; i++) {
+               unsigned int irq = port->cfg->irqs[i];
+
+               /*
+                * Certain port types won't support all of the available
+                * interrupt sources.
+                */
+               if (unlikely(!irq))
+                       continue;
+
                free_irq(port->cfg->irqs[i], port);
                kfree(port->irqstr[i]);