From 06937db21ee311ed07eba47954447245041a982d Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sat, 9 May 2026 00:13:37 +0200 Subject: [PATCH] net: ethernet: cortina: Make RX SKB per-port The SKB used to assemble packets from fragments in gmac_rx() is static local, but the Gemini has two ethernet ports, meaning there can be races between the ports on a bad day if a device is using both. Make the RX SKB a per-port variable and carry it over between invocations in the port struct instead. Zero the pointer once we call napi_gro_frags(), on error (after calling napi_free_frags()) or if the port is stopped. Zero it in some place where not strictly necessary just to emphasize what is going on. This was found by Sashiko during normal patch review. Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet") Link: https://sashiko.dev/#/patchset/20260505-gemini-ethernet-fix-v2-1-997c31d06079%40kernel.org Signed-off-by: Linus Walleij Link: https://patch.msgid.link/20260509-gemini-ethernet-fixes-v1-2-6c5d20ddc35b@kernel.org Signed-off-by: Paolo Abeni --- drivers/net/ethernet/cortina/gemini.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index 466445c9e08b..d5a56366fb43 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -122,6 +122,8 @@ struct gemini_ethernet_port { struct napi_struct napi; struct hrtimer rx_coalesce_timer; unsigned int rx_coalesce_nsecs; + struct sk_buff *rx_skb; + unsigned int freeq_refill; struct gmac_txq txq[TX_QUEUE_NUM]; unsigned int txq_order; @@ -1442,10 +1444,10 @@ static unsigned int gmac_rx(struct net_device *netdev, unsigned int budget) unsigned short m = (1 << port->rxq_order) - 1; struct gemini_ethernet *geth = port->geth; void __iomem *ptr_reg = port->rxq_rwptr; + struct sk_buff *skb = port->rx_skb; unsigned int frame_len, frag_len; struct gmac_rxdesc *rx = NULL; struct gmac_queue_page *gpage; - static struct sk_buff *skb; union gmac_rxdesc_0 word0; union gmac_rxdesc_1 word1; union gmac_rxdesc_3 word3; @@ -1504,6 +1506,7 @@ static unsigned int gmac_rx(struct net_device *netdev, unsigned int budget) if (skb) { napi_free_frags(&port->napi); port->stats.rx_dropped++; + skb = NULL; } skb = gmac_skb_if_good_frame(port, word0, frame_len); @@ -1554,6 +1557,7 @@ static unsigned int gmac_rx(struct net_device *netdev, unsigned int budget) port->stats.rx_dropped++; } + port->rx_skb = skb; writew(r, ptr_reg); return budget; } @@ -1881,6 +1885,7 @@ static int gmac_stop(struct net_device *netdev) gmac_disable_tx_rx(netdev); gmac_stop_dma(port); napi_disable(&port->napi); + port->rx_skb = NULL; gmac_enable_irq(netdev, 0); gmac_cleanup_rxq(netdev);