diff options
Diffstat (limited to 'target/linux/lantiq/patches-5.10/0704-v5.16-net-lantiq_xrx200-increase-buffer-reservation.patch')
| -rw-r--r-- | target/linux/lantiq/patches-5.10/0704-v5.16-net-lantiq_xrx200-increase-buffer-reservation.patch | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/target/linux/lantiq/patches-5.10/0704-v5.16-net-lantiq_xrx200-increase-buffer-reservation.patch b/target/linux/lantiq/patches-5.10/0704-v5.16-net-lantiq_xrx200-increase-buffer-reservation.patch new file mode 100644 index 0000000000..77c0eb6354 --- /dev/null +++ b/target/linux/lantiq/patches-5.10/0704-v5.16-net-lantiq_xrx200-increase-buffer-reservation.patch @@ -0,0 +1,122 @@ +From 1488fc204568f707fe2a42a913788c00a95af30e Mon Sep 17 00:00:00 2001 +From: Aleksander Jan Bajkowski <olek2@wp.pl> +Date: Fri, 17 Dec 2021 01:07:40 +0100 +Subject: [PATCH] net: lantiq_xrx200: increase buffer reservation + +If the user sets a lower mtu on the CPU port than on the switch, +then DMA inserts a few more bytes into the buffer 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. The reservation of FCS space in the +buffer has been removed as PMAC strips the FCS. + +Fixes: 998ac358019e ("net: lantiq: add support for jumbo frames") +Reported-by: Thomas Nixon <tom@tomn.co.uk> +Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> +Signed-off-by: Jakub Kicinski <kuba@kernel.org> +--- + drivers/net/ethernet/lantiq_xrx200.c | 34 ++++++++++++++++++++-------- + 1 file changed, 24 insertions(+), 10 deletions(-) + +--- a/drivers/net/ethernet/lantiq_xrx200.c ++++ b/drivers/net/ethernet/lantiq_xrx200.c +@@ -70,6 +70,8 @@ struct xrx200_priv { + struct xrx200_chan chan_tx; + struct xrx200_chan chan_rx; + ++ u16 rx_buf_size; ++ + struct net_device *net_dev; + struct device *dev; + +@@ -96,6 +98,16 @@ static void xrx200_pmac_mask(struct xrx2 + xrx200_pmac_w32(priv, val, offset); + } + ++static int xrx200_max_frame_len(int mtu) ++{ ++ return VLAN_ETH_HLEN + mtu; ++} ++ ++static int xrx200_buffer_size(int mtu) ++{ ++ return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN); ++} ++ + /* drop all the packets from the DMA ring */ + static void xrx200_flush_dma(struct xrx200_chan *ch) + { +@@ -108,8 +120,7 @@ static void xrx200_flush_dma(struct xrx2 + 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->rx_buf_size; + ch->dma.desc++; + ch->dma.desc %= LTQ_DESC_NUM; + } +@@ -157,21 +168,21 @@ static int xrx200_close(struct net_devic + + 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; +@@ -183,7 +194,7 @@ static int xrx200_alloc_skb(struct xrx20 + 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->rx_buf_size; + + return ret; + } +@@ -355,6 +366,7 @@ xrx200_change_mtu(struct net_device *net + int ret = 0; + + net_dev->mtu = new_mtu; ++ priv->rx_buf_size = xrx200_buffer_size(new_mtu); + + if (new_mtu <= old_mtu) + return ret; +@@ -374,6 +386,7 @@ xrx200_change_mtu(struct net_device *net + ret = xrx200_alloc_skb(ch_rx); + if (ret) { + net_dev->mtu = old_mtu; ++ priv->rx_buf_size = xrx200_buffer_size(old_mtu); + break; + } + dev_kfree_skb_any(skb); +@@ -504,7 +517,8 @@ static int xrx200_probe(struct platform_ + 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); + + /* load the memory ranges */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |