[netdrvr tg3] detect shared (and screaming) interrupts

drivers/net/tg3.c

@@ -2154,6 +2154,7 @@ static irqreturn_t tg3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	struct tg3 *tp = dev->priv;
 	struct tg3_hw_status *sblk = tp->hw_status;
 	unsigned long flags;
+	unsigned int handled = 1;
 
 	spin_lock_irqsave(&tp->lock, flags);
 
@@ -2184,11 +2185,13 @@ static irqreturn_t tg3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 			     	0x00000000);
 			tr32(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW);
 		}
+	} else {	/* shared interrupt */
+		handled = 0;
 	}
 
 	spin_unlock_irqrestore(&tp->lock, flags);
 
-	return IRQ_HANDLED;
+	return IRQ_RETVAL(handled);
 }
 
 static void tg3_init_rings(struct tg3 *);