[ 3.8.y.z extended stable ] Patch "net: sh_eth: fix incorrect RX length error if R8A7740" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: sh_eth: fix incorrect RX length error if R8A7740

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From ae6000cc9e814580496f3e99ae8de55add1cbe22 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
Date: Thu, 13 Jun 2013 10:15:45 +0900
Subject: net: sh_eth: fix incorrect RX length error if R8A7740

[ Upstream commit dd019897358b815f7828dab90b51d51df4d3658d ]

This patch fixes an issue that the driver increments the "RX length error"
on every buffer in sh_eth_rx() if the R8A7740.
This patch also adds a description about the Receive Frame Status bits.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/ethernet/renesas/sh_eth.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 3d70586..520161c 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1102,16 +1102,23 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 		desc_status = edmac_to_cpu(mdp, rxdesc->status);
 		pkt_len = rxdesc->frame_length;

-#if defined(CONFIG_ARCH_R8A7740)
-		desc_status >>= 16;
-#endif
-
 		if (--boguscnt < 0)
 			break;

 		if (!(desc_status & RDFEND))
 			ndev->stats.rx_length_errors++;

+#if defined(CONFIG_ARCH_R8A7740)
+		/*
+		 * In case of almost all GETHER/ETHERs, the Receive Frame State
+		 * (RFS) bits in the Receive Descriptor 0 are from bit 9 to
+		 * bit 0. However, in case of the R8A7740's GETHER, the RFS
+		 * bits are from bit 25 to bit 16. So, the driver needs right
+		 * shifting by 16.
+		 */
+		desc_status >>= 16;
+#endif
+
 		if (desc_status & (RD_RFS1 | RD_RFS2 | RD_RFS3 | RD_RFS4 |
 				   RD_RFS5 | RD_RFS6 | RD_RFS10)) {
 			ndev->stats.rx_errors++;
--
1.8.1.2