net: sh_eth: fix the condition to fix the cur_tx/dirty_rx

The following commit couldn't work if the RMCR is not set to 1.

"net: sh_eth: fix the rxdesc pointer when rx descriptor empty happens"
commit id 79fba9f51755c704c0a7d7b7f0df10874dc0a744

If RMCR is not set, the controller will clear the EDRRR after it received
a frame. In this case, the driver doesn't need to fix the value of
cur_rx/dirty_rx. The driver only needs it when the controll detects
receive descriptors are empty.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 667169b82526..79bf09b41971 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1011,7 +1011,7 @@ static int sh_eth_txfree(struct net_device *ndev)
 }
 
 /* Packet receive function */
-static int sh_eth_rx(struct net_device *ndev)
+static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 {
         struct sh_eth_private *mdp = netdev_priv(ndev);
         struct sh_eth_rxdesc *rxdesc;
@@ -1102,9 +1102,11 @@ static int sh_eth_rx(struct net_device *ndev)
         /* Restart Rx engine if stopped. */
         /* If we don't need to check status, don't. -KDU */
         if (!(sh_eth_read(ndev, EDRRR) & EDRRR_R)) {
-                /* fix the values for the next receiving */
-                mdp->cur_rx = mdp->dirty_rx = (sh_eth_read(ndev, RDFAR) -
-                                               sh_eth_read(ndev, RDLAR)) >> 4;
+                /* fix the values for the next receiving if RDE is set */
+                if (intr_status & EESR_RDE)
+                        mdp->cur_rx = mdp->dirty_rx =
+                                (sh_eth_read(ndev, RDFAR) -
+                                 sh_eth_read(ndev, RDLAR)) >> 4;
                 sh_eth_write(ndev, EDRRR_R, EDRRR);
         }
 
@@ -1273,7 +1275,7 @@ static irqreturn_t sh_eth_interrupt(int irq, void *netdev)
                         EESR_RTSF | /* short frame recv */
                         EESR_PRE  | /* PHY-LSI recv error */
                         EESR_CERF)){ /* recv frame CRC error */
-                sh_eth_rx(ndev);
+                sh_eth_rx(ndev, intr_status);
         }
 
         /* Tx Check */