From: Oleksij Rempel Date: Thu, 5 Mar 2026 14:34:27 +0000 (+0100) Subject: net: usb: lan78xx: fix TX byte statistics for small packets X-Git-Tag: v7.0-rc4~37^2~26^2~2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=50988747c30df47b73b787f234f746027cb7ec6c;p=thirdparty%2Fkernel%2Flinux.git net: usb: lan78xx: fix TX byte statistics for small packets Account for hardware auto-padding in TX byte counters to reflect actual wire traffic. The LAN7850 hardware automatically pads undersized frames to the minimum Ethernet frame length (ETH_ZLEN, 60 bytes). However, the driver tracks the network statistics based on the unpadded socket buffer length. This results in the tx_bytes counter under-reporting the actual physical bytes placed on the Ethernet wire for small packets (like short ARP or ICMP requests). Use max_t() to ensure the transmission statistics accurately account for the hardware-generated padding. Fixes: d383216a7efe ("lan78xx: Introduce Tx URB processing improvements") Cc: stable@vger.kernel.org Signed-off-by: Oleksij Rempel Link: https://patch.msgid.link/20260305143429.530909-3-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index 1c8f69190378..507dbcf3b7b0 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -4178,7 +4178,7 @@ static struct skb_data *lan78xx_tx_buf_fill(struct lan78xx_net *dev, } tx_data += len; - entry->length += len; + entry->length += max_t(unsigned int, len, ETH_ZLEN); entry->num_of_packet += skb_shinfo(skb)->gso_segs ?: 1; dev_kfree_skb_any(skb);