bus: omap_l3_noc: Correct returning IRQ_HANDLED unconditionally in the irq handler

commit c4cf0935 upstream.

Correct returning IRQ_HANDLED unconditionally in the irq handler.
Return IRQ_NONE for some interrupt which we do not expect to be
handled in this handler. This prevents kernel stalling with back
to back spurious interrupts.

Fixes: 2722e56d ("OMAP4: l3: Introduce l3-interconnect error handling driver")
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
[bwh: Backported to 3.2: adjust filename, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/arm/mach-omap2/omap_l3_noc.c

@@ -121,11 +121,15 @@ static irqreturn_t l3_interrupt_handler(int irq, void *_l3)
 				/* Nothing to be handled here as of now */
 				break;
 			}
-		/* Error found so break the for loop */
-		break;
+			/* Error found so break the for loop */
+			return IRQ_HANDLED;
 		}
 	}
-	return IRQ_HANDLED;
+
+	dev_err(l3->dev, "L3 %s IRQ not handled!!\n",
+		inttype ? "debug" : "application");
+
+	return IRQ_NONE;
 }
 
 static int __devinit omap4_l3_probe(struct platform_device *pdev)