@@ -71,6 +71,9 @@ struct xrx200_priv {
struct xrx200_chan chan_tx;
struct xrx200_chan chan_rx;
+ u16 max_frame_len;
+ u16 rx_buf_size;
+
struct net_device *net_dev;
struct device *dev;
@@ -97,6 +100,16 @@ static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
xrx200_pmac_w32(priv, val, offset);
}
+static inline int xrx200_max_frame_len(int mtu)
+{
+ return VLAN_ETH_HLEN + mtu + ETH_FCS_LEN;
+}
+
+static inline int xrx200_buffer_size(int mtu)
+{
+ return round_up(xrx200_max_frame_len(mtu) - 1, 4 * XRX200_DMA_BURST_LEN);
+}
+
/* drop all the packets from the DMA ring */
static void xrx200_flush_dma(struct xrx200_chan *ch)
{
@@ -109,8 +122,7 @@ static void xrx200_flush_dma(struct xrx200_chan *ch)
break;
desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
- (ch->priv->net_dev->mtu + VLAN_ETH_HLEN +
- ETH_FCS_LEN);
+ ch->priv->max_frame_len;
ch->dma.desc++;
ch->dma.desc %= LTQ_DESC_NUM;
}
@@ -158,21 +170,21 @@ static int xrx200_close(struct net_device *net_dev)
static int xrx200_alloc_skb(struct xrx200_chan *ch)
{
- int len = ch->priv->net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
struct sk_buff *skb = ch->skb[ch->dma.desc];
+ struct xrx200_priv *priv = ch->priv;
dma_addr_t mapping;
int ret = 0;
- ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
- len);
+ ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(priv->net_dev,
+ priv->rx_buf_size);
if (!ch->skb[ch->dma.desc]) {
ret = -ENOMEM;
goto skip;
}
- mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
- len, DMA_FROM_DEVICE);
- if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
+ mapping = dma_map_single(priv->dev, ch->skb[ch->dma.desc]->data,
+ priv->rx_buf_size, DMA_FROM_DEVICE);
+ if (unlikely(dma_mapping_error(priv->dev, mapping))) {
dev_kfree_skb_any(ch->skb[ch->dma.desc]);
ch->skb[ch->dma.desc] = skb;
ret = -ENOMEM;
@@ -184,7 +196,7 @@ static int xrx200_alloc_skb(struct xrx200_chan *ch)
wmb();
skip:
ch->dma.desc_base[ch->dma.desc].ctl =
- LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | len;
+ LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | priv->max_frame_len;
return ret;
}
@@ -356,6 +368,8 @@ xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
int ret = 0;
net_dev->mtu = new_mtu;
+ priv->rx_buf_size = xrx200_buffer_size(new_mtu);
+ priv->max_frame_len = xrx200_max_frame_len(new_mtu);
if (new_mtu <= old_mtu)
return ret;
@@ -375,6 +389,8 @@ xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
ret = xrx200_alloc_skb(ch_rx);
if (ret) {
net_dev->mtu = old_mtu;
+ priv->rx_buf_size = xrx200_buffer_size(old_mtu);
+ priv->max_frame_len = xrx200_max_frame_len(old_mtu);
break;
}
dev_kfree_skb_any(skb);
@@ -505,7 +521,9 @@ static int xrx200_probe(struct platform_device *pdev)
net_dev->netdev_ops = &xrx200_netdev_ops;
SET_NETDEV_DEV(net_dev, dev);
net_dev->min_mtu = ETH_ZLEN;
- net_dev->max_mtu = XRX200_DMA_DATA_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;
+ net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
+ priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
+ priv->max_frame_len = xrx200_max_frame_len(ETH_DATA_LEN);
/* load the memory ranges */
priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
If the user sets a smaller mtu on the CPU port than on the switch, then DMA inserts a few more bytes than expected. In the worst case, it may exceed the size of the buffer. The experiments showed that the buffer should be a multiple of the burst length value. This patch rounds the length of the rx buffer upwards and fixes this bug. Fixes: 998ac358019e ("net: lantiq: add support for jumbo frames") Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> --- drivers/net/ethernet/lantiq_xrx200.c | 38 ++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 10 deletions(-)