From 8d520b4de3edca4f4fb242b5ddc659b6a9b9e65e Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Thu, 28 Jan 2021 23:01:54 +0100 Subject: [PATCH] r8169: work around RTL8125 UDP hw bug It was reported that on RTL8125 network breaks under heavy UDP load, e.g. torrent traffic ([0], from comment 27). Realtek confirmed a hw bug and provided me with a test version of the r8125 driver including a workaround. Tests confirmed that the workaround fixes the issue. I modified the original version of the workaround to meet mainline code style. [0] https://bugzilla.kernel.org/show_bug.cgi?id=209839 v2: - rebased to net v3: - make rtl_skb_is_udp() more robust and use skb_header_pointer() to access the ip(v6) header v4: - remove dependency on ptp_classify.h - replace magic number with offsetof(struct udphdr, len) Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125") Tested-by: xplo Signed-off-by: Heiner Kallweit Acked-by: Willem de Bruijn Link: https://lore.kernel.org/r/6e453d49-1801-e6de-d5f7-d7e6c7526c8f@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/realtek/r8169_main.c | 71 ++++++++++++++++++++++++++++--- 1 file changed, 65 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index a569abe7f5ef..f2269c9f5f05 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4046,17 +4046,72 @@ err_out: return -EIO; } -static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp) +static bool rtl_skb_is_udp(struct sk_buff *skb) +{ + int no = skb_network_offset(skb); + struct ipv6hdr *i6h, _i6h; + struct iphdr *ih, _ih; + + switch (vlan_get_protocol(skb)) { + case htons(ETH_P_IP): + ih = skb_header_pointer(skb, no, sizeof(_ih), &_ih); + return ih && ih->protocol == IPPROTO_UDP; + case htons(ETH_P_IPV6): + i6h = skb_header_pointer(skb, no, sizeof(_i6h), &_i6h); + return i6h && i6h->nexthdr == IPPROTO_UDP; + default: + return false; + } +} + +#define RTL_MIN_PATCH_LEN 47 + +/* see rtl8125_get_patch_pad_len() in r8125 vendor driver */ +static unsigned int rtl8125_quirk_udp_padto(struct rtl8169_private *tp, + struct sk_buff *skb) { + unsigned int padto = 0, len = skb->len; + + if (rtl_is_8125(tp) && len < 128 + RTL_MIN_PATCH_LEN && + rtl_skb_is_udp(skb) && skb_transport_header_was_set(skb)) { + unsigned int trans_data_len = skb_tail_pointer(skb) - + skb_transport_header(skb); + + if (trans_data_len >= offsetof(struct udphdr, len) && + trans_data_len < RTL_MIN_PATCH_LEN) { + u16 dest = ntohs(udp_hdr(skb)->dest); + + /* dest is a standard PTP port */ + if (dest == 319 || dest == 320) + padto = len + RTL_MIN_PATCH_LEN - trans_data_len; + } + + if (trans_data_len < sizeof(struct udphdr)) + padto = max_t(unsigned int, padto, + len + sizeof(struct udphdr) - trans_data_len); + } + + return padto; +} + +static unsigned int rtl_quirk_packet_padto(struct rtl8169_private *tp, + struct sk_buff *skb) +{ + unsigned int padto; + + padto = rtl8125_quirk_udp_padto(tp, skb); + switch (tp->mac_version) { case RTL_GIGA_MAC_VER_34: case RTL_GIGA_MAC_VER_60: case RTL_GIGA_MAC_VER_61: case RTL_GIGA_MAC_VER_63: - return true; + padto = max_t(unsigned int, padto, ETH_ZLEN); default: - return false; + break; } + + return padto; } static void rtl8169_tso_csum_v1(struct sk_buff *skb, u32 *opts) @@ -4128,9 +4183,10 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp, opts[1] |= transport_offset << TCPHO_SHIFT; } else { - if (unlikely(skb->len < ETH_ZLEN && rtl_test_hw_pad_bug(tp))) - /* eth_skb_pad would free the skb on error */ - return !__skb_put_padto(skb, ETH_ZLEN, false); + unsigned int padto = rtl_quirk_packet_padto(tp, skb); + + /* skb_padto would free the skb on error */ + return !__skb_put_padto(skb, padto, false); } return true; @@ -4307,6 +4363,9 @@ static netdev_features_t rtl8169_features_check(struct sk_buff *skb, if (skb->len < ETH_ZLEN) features &= ~NETIF_F_CSUM_MASK; + if (rtl_quirk_packet_padto(tp, skb)) + features &= ~NETIF_F_CSUM_MASK; + if (transport_offset > TCPHO_MAX && rtl_chip_supports_csum_v2(tp)) features &= ~NETIF_F_CSUM_MASK; -- 2.11.0