From: Ding Meng When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected, often resulting in incorrect or negative values such as "HW raw -121948.050407424". This occurs because disabling CONFIG_NET_RX_BUSY_POLL disables the SKB NAPI mapping in __skb_mark_napi_id(). Consequently, get_timestamp() fails to perform its driver lookup, and the igc driver's struct net_device_ops::ndo_get_tstamp is never invoked. Instead, get_timestamp() falls back to use shhwtstamps(skb)->hwtstamp, a field that the driver has not populated. This results in incorrect timestamps. Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled. The "igc_adapter" is passed to igc_construct_skb() to enable igc_ptp_rx_pktstamp() to access the necessary adapter details for adjusting the timestamp. Test case: Disable CONFIG_NET_RX_BUSY_POLL. Sender: # tools/testing/selftests/net/timestamping en0 \ SOF_TIMESTAMPING_TX_HARDWARE PTPV2 IP_MULTICAST_LOOP Receiver: # tools/testing/selftests/net/timestamping en0 \ SOF_TIMESTAMPING_RX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE PTPV2 Before patch, receiver prints HW raw -121948.050407424 After patch, receiver prints HW raw 1760648763.746974064 Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()") Cc: stable@vger.kernel.org Co-developed-by: Florian Bezdeka Signed-off-by: Florian Bezdeka Signed-off-by: Ding Meng Reviewed-by: Aleksandr Loktionov Reviewed-by: Piotr Kwapulinski Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/igc/igc_main.c | 41 ++++++++++++++++------- 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 1fb5f3cbe93c..95f7747b347b 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -1989,7 +1989,29 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, return skb; } -static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, +static void igc_construct_skb_timestamps(struct igc_adapter *adapter, + struct sk_buff *skb, + struct igc_xdp_buff *ctx) +{ +#ifndef CONFIG_NET_RX_BUSY_POLL + struct igc_inline_rx_tstamps *tstamps; +#endif + + if (!ctx->rx_ts) + return; + +#ifndef CONFIG_NET_RX_BUSY_POLL + tstamps = ctx->rx_ts; + skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter, + tstamps->timer0); +#else + skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV; + skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; +#endif +} + +static struct sk_buff *igc_construct_skb(struct igc_adapter *adapter, + struct igc_ring *rx_ring, struct igc_rx_buffer *rx_buffer, struct igc_xdp_buff *ctx) { @@ -2010,10 +2032,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, if (unlikely(!skb)) return NULL; - if (ctx->rx_ts) { - skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV; - skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; - } + igc_construct_skb_timestamps(adapter, skb, ctx); /* Determine available headroom for copy */ headlen = size; @@ -2683,7 +2702,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) else if (ring_uses_build_skb(rx_ring)) skb = igc_build_skb(rx_ring, rx_buffer, &ctx.xdp); else - skb = igc_construct_skb(rx_ring, rx_buffer, &ctx); + skb = igc_construct_skb(adapter, rx_ring, rx_buffer, &ctx); /* exit if we failed to retrieve a buffer */ if (!xdp_res && !skb) { @@ -2735,7 +2754,8 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) return total_packets; } -static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, +static struct sk_buff *igc_construct_skb_zc(struct igc_adapter *adapter, + struct igc_ring *ring, struct igc_xdp_buff *ctx) { struct xdp_buff *xdp = &ctx->xdp; @@ -2757,10 +2777,7 @@ static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, __skb_pull(skb, metasize); } - if (ctx->rx_ts) { - skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV; - skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; - } + igc_construct_skb_timestamps(adapter, skb, ctx); return skb; } @@ -2772,7 +2789,7 @@ static void igc_dispatch_skb_zc(struct igc_q_vector *q_vector, struct igc_ring *ring = q_vector->rx.ring; struct sk_buff *skb; - skb = igc_construct_skb_zc(ring, ctx); + skb = igc_construct_skb_zc(q_vector->adapter, ring, ctx); if (!skb) { ring->rx_stats.alloc_failed++; set_bit(IGC_RING_FLAG_RX_ALLOC_FAILED, &ring->flags); -- 2.47.1