diff options
| author | Markus Stockhausen | 2026-02-12 13:53:11 +0000 |
|---|---|---|
| committer | Robert Marko | 2026-02-19 09:47:55 +0000 |
| commit | 47d0773d7deb0f9d9670bdf0d9e13bd863cbdc4c (patch) | |
| tree | a59959f49be357dc4739942c164121273342e457 | |
| parent | a36ab12454e401bdc581e9f96458fa860ddfce73 (diff) | |
| download | openwrt-47d0773d7deb0f9d9670bdf0d9e13bd863cbdc4c.tar.gz | |
realtek: eth: cleanup packet length calculation
During transmit the driver must adapt the packet length. The
hardware requires at least a memory space of ETH_ZLEN bytes
data plus four bytes for layer 2 FCS. This was calculated
(somehow) but skb->len never got updated and for the minimum
length a RTL838x specific workaround was in place. Clean up
the code and use skb_put_padto() so the length change gets
reflected in skb->len.
While we are here drop zeroing DSA tag because it will be
overwritten by hardware for FCS.
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/21999
Signed-off-by: Robert Marko <robimarko@gmail.com>
| -rw-r--r-- | target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c index 7a557afb64..65843f822d 100644 --- a/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c +++ b/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c @@ -8,6 +8,7 @@ #include <linux/etherdevice.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/minmax.h> #include <linux/platform_device.h> #include <linux/sched.h> #include <linux/slab.h> @@ -977,16 +978,15 @@ static int rteth_start_xmit(struct sk_buff *skb, struct net_device *netdev) skb->data[len - 3] < ctrl->r->cpu_port && skb->data[len - 2] == 0x10 && skb->data[len - 1] == 0x00) { - /* DSA tag, reuse space for CRC */ dest_port = skb->data[len - 3]; - skb->data[len - 4] = skb->data[len - 3] = 0; - skb->data[len - 2] = skb->data[len - 1] = 0; + /* space will be reused for 4 byte layer 2 FCS */ } else { - /* No DSA tag, add space for CRC */ - len += 4; + /* No DSA tag, add space for 4 byte layer 2 FCS */ + len += ETH_FCS_LEN; } - if (unlikely(skb_padto(skb, len))) { + len = max(ETH_ZLEN + ETH_FCS_LEN, len); + if (unlikely(skb_put_padto(skb, len))) { netdev->stats.tx_errors++; dev_warn(dev, "skb pad failed\n"); @@ -1005,7 +1005,7 @@ static int rteth_start_xmit(struct sk_buff *skb, struct net_device *netdev) return NETDEV_TX_BUSY; } - packet->dma = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE); + packet->dma = dma_map_single(dev, skb->data, len, DMA_TO_DEVICE); if (unlikely(dma_mapping_error(dev, packet->dma))) { dev_kfree_skb_any(skb); netdev->stats.tx_errors++; @@ -1019,12 +1019,6 @@ static int rteth_start_xmit(struct sk_buff *skb, struct net_device *netdev) dev_kfree_skb_any(packet->skb); } - if (ctrl->r->family_id == RTL8380_FAMILY_ID) { - /* On RTL8380 SoCs, small packet lengths being sent need adjustments */ - if (len < ETH_ZLEN - 4) - len -= 4; - } - if (dest_port >= 0) ctrl->r->create_tx_header(packet, dest_port, 0); // TODO ok to set prio to 0? |