1 From 998ac358019e491217e752bc6dcbb3afb2a6fa3e Mon Sep 17 00:00:00 2001
2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
3 Date: Sun, 19 Sep 2021 20:24:28 +0200
4 Subject: [PATCH] net: lantiq: add support for jumbo frames
6 Add support for jumbo frames. Full support for jumbo frames requires
7 changes in the DSA switch driver (lantiq_gswip.c).
9 Tested on BT Hone Hub 5A.
11 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
12 Signed-off-by: David S. Miller <davem@davemloft.net>
14 drivers/net/ethernet/lantiq_xrx200.c | 64 +++++++++++++++++++++++++---
15 1 file changed, 57 insertions(+), 7 deletions(-)
17 --- a/drivers/net/ethernet/lantiq_xrx200.c
18 +++ b/drivers/net/ethernet/lantiq_xrx200.c
20 #include <linux/clk.h>
21 #include <linux/delay.h>
23 +#include <linux/if_vlan.h>
25 #include <linux/of_net.h>
26 #include <linux/of_platform.h>
31 -#define XRX200_DMA_DATA_LEN 0x600
32 +#define XRX200_DMA_DATA_LEN (SZ_64K - 1)
33 #define XRX200_DMA_RX 0
34 #define XRX200_DMA_TX 1
36 @@ -106,7 +108,8 @@ static void xrx200_flush_dma(struct xrx2
39 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
40 - XRX200_DMA_DATA_LEN;
41 + (ch->priv->net_dev->mtu + VLAN_ETH_HLEN +
44 ch->dma.desc %= LTQ_DESC_NUM;
46 @@ -154,19 +157,20 @@ static int xrx200_close(struct net_devic
48 static int xrx200_alloc_skb(struct xrx200_chan *ch)
50 + int len = ch->priv->net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
51 struct sk_buff *skb = ch->skb[ch->dma.desc];
55 ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
56 - XRX200_DMA_DATA_LEN);
58 if (!ch->skb[ch->dma.desc]) {
63 mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
64 - XRX200_DMA_DATA_LEN, DMA_FROM_DEVICE);
65 + len, DMA_FROM_DEVICE);
66 if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
67 dev_kfree_skb_any(ch->skb[ch->dma.desc]);
68 ch->skb[ch->dma.desc] = skb;
69 @@ -179,8 +183,7 @@ static int xrx200_alloc_skb(struct xrx20
72 ch->dma.desc_base[ch->dma.desc].ctl =
73 - LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
74 - XRX200_DMA_DATA_LEN;
75 + LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | len;
79 @@ -340,10 +343,57 @@ err_drop:
84 +xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
86 + struct xrx200_priv *priv = netdev_priv(net_dev);
87 + struct xrx200_chan *ch_rx = &priv->chan_rx;
88 + int old_mtu = net_dev->mtu;
89 + bool running = false;
90 + struct sk_buff *skb;
94 + net_dev->mtu = new_mtu;
96 + if (new_mtu <= old_mtu)
99 + running = netif_running(net_dev);
101 + napi_disable(&ch_rx->napi);
102 + ltq_dma_close(&ch_rx->dma);
105 + xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
106 + curr_desc = ch_rx->dma.desc;
108 + for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
109 + ch_rx->dma.desc++) {
110 + skb = ch_rx->skb[ch_rx->dma.desc];
111 + ret = xrx200_alloc_skb(ch_rx);
113 + net_dev->mtu = old_mtu;
116 + dev_kfree_skb_any(skb);
119 + ch_rx->dma.desc = curr_desc;
121 + napi_enable(&ch_rx->napi);
122 + ltq_dma_open(&ch_rx->dma);
123 + ltq_dma_enable_irq(&ch_rx->dma);
129 static const struct net_device_ops xrx200_netdev_ops = {
130 .ndo_open = xrx200_open,
131 .ndo_stop = xrx200_close,
132 .ndo_start_xmit = xrx200_start_xmit,
133 + .ndo_change_mtu = xrx200_change_mtu,
134 .ndo_set_mac_address = eth_mac_addr,
135 .ndo_validate_addr = eth_validate_addr,
137 @@ -454,7 +504,7 @@ static int xrx200_probe(struct platform_
138 net_dev->netdev_ops = &xrx200_netdev_ops;
139 SET_NETDEV_DEV(net_dev, dev);
140 net_dev->min_mtu = ETH_ZLEN;
141 - net_dev->max_mtu = XRX200_DMA_DATA_LEN;
142 + net_dev->max_mtu = XRX200_DMA_DATA_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;
144 /* load the memory ranges */
145 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);