usb: typec: tipd: Add short-circuit for no irqs

If no interrupts are set in IntEventX directly skip to the end of the
interrupt handler and return IRQ_NONE instead of IRQ_HANDLED.
This possibly allows to detect spurious interrupts if the i2c bus is fast
enough.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20210928155502.71372-4-sven@svenpeter.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tipd/core.c

@@ -479,6 +479,9 @@ static irqreturn_t tps6598x_interrupt(int irq, void *data)
 	}
 	trace_tps6598x_irq(event1, event2);
 
+	if (!(event1 | event2))
+		goto err_unlock;
+
 	if (!tps6598x_read_status(tps, &status))
 		goto err_clear_ints;
 
@@ -501,7 +504,9 @@ err_clear_ints:
 err_unlock:
 	mutex_unlock(&tps->lock);
 
-	return IRQ_HANDLED;
+	if (event1 | event2)
+		return IRQ_HANDLED;
+	return IRQ_NONE;
 }
 
 static int tps6598x_check_mode(struct tps6598x *tps)