[media] sir_ir: infinite loop in interrupt handler

Since this driver does no detection of hardware, it might be used with
a non-sir port. Escape out if we are spinning.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/media/rc/sir_ir.c b/drivers/media/rc/sir_ir.c
index e12ec50bf0bf..90a5f8fd5eea 100644
--- a/drivers/media/rc/sir_ir.c
+++ b/drivers/media/rc/sir_ir.c
@@ -183,9 +183,15 @@ static irqreturn_t sir_interrupt(int irq, void *dev_id)
         static unsigned long delt;
         unsigned long deltintr;
         unsigned long flags;
+        int counter = 0;
         int iir, lsr;
 
         while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
+                if (++counter > 256) {
+                        dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
+                        break;
+                }
+
                 switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
                 case UART_IIR_MSI:
                         (void)inb(io + UART_MSR);