ar71xx: ag71xx: calculate max frame len register value from the MTU

[openwrt.git] / target / linux / ar71xx / files / drivers / net / ethernet / atheros / ag71xx / ag71xx_main.c

diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
index a129a6f..715c1ce 100644 (file)
--- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
@@ -28,6 +28,11 @@ static int ag71xx_msg_level = -1;
 module_param_named(msg_level, ag71xx_msg_level, int, 0);
 MODULE_PARM_DESC(msg_level, "Message level (-1=defaults,0=none,...,16=all)");
 
+static inline unsigned int ag71xx_max_frame_len(unsigned int mtu)
+{
+       return ETH_HLEN + VLAN_HLEN + mtu + ETH_FCS_LEN;
+}
+
 static void ag71xx_dump_dma_regs(struct ag71xx *ag)
 {
        DBG("%s: dma_tx_ctrl=%08x, dma_tx_desc=%08x, dma_tx_status=%08x\n",
@@ -433,8 +438,8 @@ static void ag71xx_hw_setup(struct ag71xx *ag)
        ag71xx_sb(ag, AG71XX_REG_MAC_CFG2,
                  MAC_CFG2_PAD_CRC_EN | MAC_CFG2_LEN_CHECK);
 
-       /* setup max frame length */
-       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, ag->max_frame_len);
+       /* setup max frame length to zero */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, 0);
 
        /* setup FIFO configuration registers */
        ag71xx_wr(ag, AG71XX_REG_FIFO_CFG0, FIFO_CFG0_INIT);
@@ -503,6 +508,10 @@ static void ag71xx_fast_reset(struct ag71xx *ag)
        ag71xx_dma_reset(ag);
        ag71xx_hw_setup(ag);
 
+       /* setup max frame length */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL,
+                 ag71xx_max_frame_len(ag->dev->mtu));
+
        ag71xx_wr(ag, AG71XX_REG_RX_DESC, rx_ds);
        ag71xx_wr(ag, AG71XX_REG_TX_DESC, tx_ds);
        ag71xx_wr(ag, AG71XX_REG_MII_CFG, mii_reg);
@@ -607,9 +616,14 @@ void ag71xx_link_adjust(struct ag71xx *ag)
 static int ag71xx_open(struct net_device *dev)
 {
        struct ag71xx *ag = netdev_priv(dev);
+       unsigned int max_frame_len;
        int ret;
 
-       ag->rx_buf_size = ag->max_frame_len + NET_SKB_PAD + NET_IP_ALIGN;
+       max_frame_len = ag71xx_max_frame_len(dev->mtu);
+       ag->rx_buf_size = max_frame_len + NET_SKB_PAD + NET_IP_ALIGN;
+
+       /* setup max frame length */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, max_frame_len);
 
        ret = ag71xx_rings_init(ag);
        if (ret)
@@ -1052,11 +1066,15 @@ static void ag71xx_netpoll(struct net_device *dev)
 static int ag71xx_change_mtu(struct net_device *dev, int new_mtu)
 {
        struct ag71xx *ag = netdev_priv(dev);
+       unsigned int max_frame_len;
 
-       if (new_mtu < 68 ||
-           new_mtu > ag->max_frame_len - ETH_HLEN - ETH_FCS_LEN)
+       max_frame_len = ag71xx_max_frame_len(new_mtu);
+       if (new_mtu < 68 || max_frame_len > ag->max_frame_len)
                return -EINVAL;
 
+       if (netif_running(dev))
+               return -EBUSY;
+
        dev->mtu = new_mtu;
        return 0;
 }
@@ -1124,6 +1142,9 @@ static int ag71xx_probe(struct platform_device *pdev)
                goto err_out;
        }
 
+       if (!pdata->max_frame_len || !pdata->desc_pktlen_mask)
+               return -EINVAL;
+
        SET_NETDEV_DEV(dev, &pdev->dev);
 
        ag = netdev_priv(dev);
@@ -1169,8 +1190,8 @@ static int ag71xx_probe(struct platform_device *pdev)
        ag->tx_ring.size = AG71XX_TX_RING_SIZE_DEFAULT;
        ag->rx_ring.size = AG71XX_RX_RING_SIZE_DEFAULT;
 
-       ag->max_frame_len = AG71XX_TX_MTU_LEN;
-       ag->desc_pktlen_mask = DESC_PKTLEN_MASK;
+       ag->max_frame_len = pdata->max_frame_len;
+       ag->desc_pktlen_mask = pdata->desc_pktlen_mask;
 
        ag->stop_desc = dma_alloc_coherent(NULL,
                sizeof(struct ag71xx_desc), &ag->stop_desc_dma, GFP_KERNEL);