NFS/TCP/IPv6 acting strangely in 4.2

Hi,

On Wed, Sep 16, 2015 at 06:53:57AM +0000, Damien Th?bault wrote:

On Fri, 2015-09-11 at 12:38 +0100, Russell King - ARM Linux wrote:

quoted

I have a recent Marvell Armada 388 board here which uses the mvneta
driver.  I'm seeing some weird effects with NFS with it acting as a
client.

Hello,

I'm upgrading a Marvelle Armada 370 board using the mvneta driver from
4.0 to 4.2 and noticed issues with NFS booting.
Basically, most of the time init returns with an error code, or
programs segfault or throw illegal instructions.

Since it worked fine on 4.0 I bisected until I found commit
a84e32894191cfcbffa54180d78d7d4654d56c20 "net: mvneta: fix refilling
for Rx DMA buffers".

If I revert this commit, everything seems to get back to normal.
Could you try it ? The two issues look very similar.

I'm not sure but I'm seeing that the accounting was changed by this
patch without being certain of the implications; if the revert above
works, it would be nice to try to only apply this just to see if
that's indeed an accounting error or not :

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 62e48bc..4205867 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c

@@ -1463,6 +1463,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
 {
 	struct net_device *dev = pp->dev;
 	int rx_done;
+	int missed = 0;
 	u32 rcvd_pkts = 0;
 	u32 rcvd_bytes = 0;
 

@@ -1527,6 +1528,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
 		if (err) {
 			netdev_err(dev, "Linux processing - Can't refill\n");
 			rxq->missed++;
+			missed++;
 			goto err_drop_frame;
 		}
 

@@ -1561,7 +1563,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
 	}
 
 	/* Update rxq management counters */
-	mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_done);
+	mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_done - missed);
 
 	return rx_done;
 }

Regards,
Willy