net: mvmdio: fix interrupt timeout handling

This version corrects the whitespace issue. orion_mdio_wait_ready uses wait_event_timeout to wait for the SMI interrupt to fire. wait_event_timeout waits for between "timeout - 1" and "timeout" jiffies. In this case a 1ms timeout when HZ is 1000 results in a wait of 0 to 1 jiffies, causing premature timeouts. This fix ensures a minimum timeout of 2 jiffies, ensuring wait_event_timeout will always wait at least 1 jiffie. Issue reported by Nicolas Schichan. Tested-by: Nicolas Schichan <[email protected]> Signed-off-by: Leigh Brown <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Dec 20, 2013 · 1a1f20b · 1a1f20b
1 parent a4f6363
commit 1a1f20b
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
@@ -92,6 +92,12 @@ static int orion_mdio_wait_ready(struct mii_bus *bus)
 			if (time_is_before_jiffies(end))
 				++timedout;
 	        } else {
+			/* wait_event_timeout does not guarantee a delay of at
+			 * least one whole jiffie, so timeout must be no less
+			 * than two.
+			 */
+			if (timeout < 2)
+				timeout = 2;
 			wait_event_timeout(dev->smi_busy_wait,
 				           orion_mdio_smi_is_done(dev),
 				           timeout);