skge: changing MTU while running causes problems

Rather than bring network down/up when changing MTU,
only need to impact receiver.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 44 insertions, 7 deletions

diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index e593585f8bf7..d5c10fd93bf4 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -2544,6 +2544,15 @@ static int skge_up(struct net_device *dev)
         return err;
 }
 
+/* stop receiver */
+static void skge_rx_stop(struct skge_hw *hw, int port)
+{
+        skge_write8(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_STOP);
+        skge_write32(hw, RB_ADDR(port ? Q_R2 : Q_R1, RB_CTRL),
+                     RB_RST_SET|RB_DIS_OP_MD);
+        skge_write32(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_SET_RESET);
+}
+
 static int skge_down(struct net_device *dev)
 {
         struct skge_port *skge = netdev_priv(dev);
@@ -2595,11 +2604,8 @@ static int skge_down(struct net_device *dev)
 
         /* Reset the RAM Buffer async Tx queue */
         skge_write8(hw, RB_ADDR(port == 0 ? Q_XA1 : Q_XA2, RB_CTRL), RB_RST_SET);
-        /* stop receiver */
-        skge_write8(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_STOP);
-        skge_write32(hw, RB_ADDR(port ? Q_R2 : Q_R1, RB_CTRL),
-                     RB_RST_SET|RB_DIS_OP_MD);
-        skge_write32(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_SET_RESET);
+
+        skge_rx_stop(hw, port);
 
         if (hw->chip_id == CHIP_ID_GENESIS) {
                 skge_write8(hw, SK_REG(port, TX_MFF_CTRL2), MFF_RST_SET);
@@ -2782,7 +2788,11 @@ static void skge_tx_timeout(struct net_device *dev)
 
 static int skge_change_mtu(struct net_device *dev, int new_mtu)
 {
+        struct skge_port *skge = netdev_priv(dev);
+        struct skge_hw *hw = skge->hw;
+        int port = skge->port;
         int err;
+        u16 ctl, reg;
 
         if (new_mtu < ETH_ZLEN || new_mtu > ETH_JUMBO_MTU)
                 return -EINVAL;
@@ -2792,13 +2802,40 @@ static int skge_change_mtu(struct net_device *dev, int new_mtu)
                 return 0;
         }
 
-        skge_down(dev);
+        skge_write32(hw, B0_IMSK, 0);
+        dev->trans_start = jiffies;     /* prevent tx timeout */
+        netif_stop_queue(dev);
+        napi_disable(&skge->napi);
+
+        ctl = gma_read16(hw, port, GM_GP_CTRL);
+        gma_write16(hw, port, GM_GP_CTRL, ctl & ~GM_GPCR_RX_ENA);
+
+        skge_rx_clean(skge);
+        skge_rx_stop(hw, port);
 
         dev->mtu = new_mtu;
 
-        err = skge_up(dev);
+        reg = GM_SMOD_VLAN_ENA | IPG_DATA_VAL(IPG_DATA_DEF);
+        if (new_mtu > 1500)
+                reg |= GM_SMOD_JUMBO_ENA;
+        gma_write16(hw, port, GM_SERIAL_MODE, reg);
+
+        skge_write8(hw, RB_ADDR(rxqaddr[port], RB_CTRL), RB_ENA_OP_MD);
+
+        err = skge_rx_fill(dev);
+        wmb();
+        if (!err)
+                skge_write8(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_START | CSR_IRQ_CL_F);
+        skge_write32(hw, B0_IMSK, hw->intr_mask);
+
         if (err)
                 dev_close(dev);
+        else {
+                gma_write16(hw, port, GM_GP_CTRL, ctl);
+
+                napi_enable(&skge->napi);
+                netif_wake_queue(dev);
+        }
 
         return err;
 }