[Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Ding Meng]

When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
from the NIC no longer works as expected.

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.

Fix this by populating the hwtstamp field with the correct timestamp
in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.

Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Signed-off-by: Ding Meng <meng.ding@siemens.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 8ac16808023..1da8d7aa76d 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1992,7 +1992,26 @@ 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)
+{
+	if (!ctx->rx_ts)
+		return;
+#ifdef CONFIG_NET_RX_BUSY_POLL
+	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
+	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts;
+#else
+	struct igc_inline_rx_tstamps *tstamps;
+
+	tstamps = ctx->rx_ts;
+	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
+							   tstamps->timer0);
+#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)
 {
@@ -2013,10 +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;
@@ -2686,7 +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) {
@@ -2738,7 +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;
@@ -2760,10 +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;
 }
@@ -2775,7 +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);

base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
-- 
2.47.3

[Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Ding Meng via Intel-wired-lan]

When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
from the NIC no longer works as expected.

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.

Fix this by populating the hwtstamp field with the correct timestamp
in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.

Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Signed-off-by: Ding Meng <meng.ding@siemens.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 8ac16808023..1da8d7aa76d 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1992,7 +1992,26 @@ 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)
+{
+	if (!ctx->rx_ts)
+		return;
+#ifdef CONFIG_NET_RX_BUSY_POLL
+	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
+	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts;
+#else
+	struct igc_inline_rx_tstamps *tstamps;
+
+	tstamps = ctx->rx_ts;
+	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
+							   tstamps->timer0);
+#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)
 {
@@ -2013,10 +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;
@@ -2686,7 +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) {
@@ -2738,7 +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;
@@ -2760,10 +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;
 }
@@ -2775,7 +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);

base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
-- 
2.47.3

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Ding Meng via Intel-wired-lan
> Sent: Monday, June 22, 2026 6:13 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka,
> Florian <florian.bezdeka@siemens.com>
> Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org;
> netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp
> reporting when NET_RX_BUSY_POLL is disabled
> 
> When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> from the NIC no longer works as expected.
> 
> 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.
> 
> Fix this by populating the hwtstamp field with the correct timestamp
> in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> 
> Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
I think, because it's a fix, it needs Cc: stable@vger.kernel.org

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

> Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Ding Meng <meng.ding@siemens.com>
> ---
>  drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++------
> -
>  1 file changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 8ac16808023..1da8d7aa76d 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -1992,7 +1992,26 @@ 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)
> +{
> +	if (!ctx->rx_ts)
> +		return;
> +#ifdef CONFIG_NET_RX_BUSY_POLL
> +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
> +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
> +	struct igc_inline_rx_tstamps *tstamps;
> +
> +	tstamps = ctx->rx_ts;
> +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
> +							   tstamps->timer0);
> +#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)
>  {
> @@ -2013,10 +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;
> @@ -2686,7 +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) {
> @@ -2738,7 +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;
> @@ -2760,10 +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;
>  }
> @@ -2775,7 +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);
> 
> base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
> --
> 2.47.3

RE: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Ding Meng via Intel-wired-lan
> Sent: Monday, June 22, 2026 6:13 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka,
> Florian <florian.bezdeka@siemens.com>
> Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org;
> netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp
> reporting when NET_RX_BUSY_POLL is disabled
> 
> When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> from the NIC no longer works as expected.
> 
> 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.
> 
> Fix this by populating the hwtstamp field with the correct timestamp
> in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> 
> Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
I think, because it's a fix, it needs Cc: stable@vger.kernel.org

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

> Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Ding Meng <meng.ding@siemens.com>
> ---
>  drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++------
> -
>  1 file changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 8ac16808023..1da8d7aa76d 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -1992,7 +1992,26 @@ 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)
> +{
> +	if (!ctx->rx_ts)
> +		return;
> +#ifdef CONFIG_NET_RX_BUSY_POLL
> +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
> +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
> +	struct igc_inline_rx_tstamps *tstamps;
> +
> +	tstamps = ctx->rx_ts;
> +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
> +							   tstamps->timer0);
> +#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)
>  {
> @@ -2013,10 +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;
> @@ -2686,7 +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) {
> @@ -2738,7 +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;
> @@ -2760,10 +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;
>  }
> @@ -2775,7 +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);
> 
> base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
> --
> 2.47.3

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Paul Menzel]

Dear Ding,


Thank you for your patch.

Am 22.06.26 um 06:13 schrieb Ding Meng via Intel-wired-lan:
> When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> from the NIC no longer works as expected.

Maybe paste some logs/errors, so it can be easier found by people with 
the same issue.

> 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.
> 
> Fix this by populating the hwtstamp field with the correct timestamp
> in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.

Maybe detail, why the adapter needs to be passed now.

Also, please describe a test case to check the change.

> Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
> Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> Signed-off-by: Ding Meng <meng.ding@siemens.com>
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
>   1 file changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index 8ac16808023..1da8d7aa76d 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -1992,7 +1992,26 @@ 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)
> +{
> +	if (!ctx->rx_ts)
> +		return;
> +#ifdef CONFIG_NET_RX_BUSY_POLL

Is there a way to do this in C instead of the pre-processor. That way 
all the code gets build tested. (Is there a config with disabled 
NET_RX_BUSY_POLL?)

> +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
> +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts;
> +#else
> +	struct igc_inline_rx_tstamps *tstamps;
> +
> +	tstamps = ctx->rx_ts;
> +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
> +							   tstamps->timer0);
> +#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)
>   {
> @@ -2013,10 +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;
> @@ -2686,7 +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) {
> @@ -2738,7 +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;
> @@ -2760,10 +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;
>   }
> @@ -2775,7 +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);

Otherwise this looks good.


Kind regards,

Paul

RE: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Kwapulinski, Piotr]

>-----Original Message-----
>From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Ding Meng via Intel-wired-lan
>Sent: Monday, June 22, 2026 6:13 AM
>To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka, Florian <florian.bezdeka@siemens.com>
>Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
>Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
>
>When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected.
>
>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.
>
>Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
>
>Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
>Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>Signed-off-by: Ding Meng <meng.ding@siemens.com>
>---
> drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
> 1 file changed, 26 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
>index 8ac16808023..1da8d7aa76d 100644
>--- a/drivers/net/ethernet/intel/igc/igc_main.c
>+++ b/drivers/net/ethernet/intel/igc/igc_main.c
>@@ -1992,7 +1992,26 @@ 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)
>+{
>+	if (!ctx->rx_ts)
>+		return;
>+#ifdef CONFIG_NET_RX_BUSY_POLL
>+	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
>+	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
>+	struct igc_inline_rx_tstamps *tstamps;
Please move at the top of the function and add:
Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com

>+
>+	tstamps = ctx->rx_ts;
>+	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
>+							   tstamps->timer0);
>+#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)
> {
>@@ -2013,10 +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;
>@@ -2686,7 +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) {
>@@ -2738,7 +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;
>@@ -2760,10 +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;
> }
>@@ -2775,7 +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);
>
>base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
>--
>2.47.3
>
>

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Kwapulinski, Piotr]

>-----Original Message-----
>From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Ding Meng via Intel-wired-lan
>Sent: Monday, June 22, 2026 6:13 AM
>To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka, Florian <florian.bezdeka@siemens.com>
>Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
>Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
>
>When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected.
>
>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.
>
>Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
>
>Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
>Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>Signed-off-by: Ding Meng <meng.ding@siemens.com>
>---
> drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
> 1 file changed, 26 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
>index 8ac16808023..1da8d7aa76d 100644
>--- a/drivers/net/ethernet/intel/igc/igc_main.c
>+++ b/drivers/net/ethernet/intel/igc/igc_main.c
>@@ -1992,7 +1992,26 @@ 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)
>+{
>+	if (!ctx->rx_ts)
>+		return;
>+#ifdef CONFIG_NET_RX_BUSY_POLL
>+	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
>+	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
>+	struct igc_inline_rx_tstamps *tstamps;
Please move at the top of the function and add:
Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com

>+
>+	tstamps = ctx->rx_ts;
>+	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
>+							   tstamps->timer0);
>+#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)
> {
>@@ -2013,10 +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;
>@@ -2686,7 +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) {
>@@ -2738,7 +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;
>@@ -2760,10 +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;
> }
>@@ -2775,7 +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);
>
>base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
>--
>2.47.3
>
>

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Florian Bezdeka via Intel-wired-lan]

On Tue, 2026-06-23 at 09:46 +0000, Kwapulinski, Piotr wrote:
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Ding Meng via Intel-wired-lan
> > Sent: Monday, June 22, 2026 6:13 AM
> > To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka, Florian <florian.bezdeka@siemens.com>
> > Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> > Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
> > 
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected.
> > 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> > 
> > Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
> > Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Ding Meng <meng.ding@siemens.com>
> > ---
> > drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
> > 1 file changed, 26 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> > index 8ac16808023..1da8d7aa76d 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_main.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> > @@ -1992,7 +1992,26 @@ 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)
> > +{
> > +	if (!ctx->rx_ts)
> > +		return;
> > +#ifdef CONFIG_NET_RX_BUSY_POLL
> > +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
> > +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
> > +	struct igc_inline_rx_tstamps *tstamps;
> Please move at the top of the function and add:

That would trigger a "unused variable" warning in the
CONFIG_NET_RX_BUSY_POLL case.

Btw: I was really confused that the #else statement moved to the end of
the previous line. Might someone be using a wrongly configured mail
client here?

Florian

> Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com
> 
> > +
> > +	tstamps = ctx->rx_ts;
> > +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
> > +							   tstamps->timer0);
> > +#endif
> > +}
> > +

[snip]

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Florian Bezdeka]

On Tue, 2026-06-23 at 09:46 +0000, Kwapulinski, Piotr wrote:
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Ding Meng via Intel-wired-lan
> > Sent: Monday, June 22, 2026 6:13 AM
> > To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka, Florian <florian.bezdeka@siemens.com>
> > Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> > Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
> > 
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected.
> > 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> > 
> > Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
> > Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Ding Meng <meng.ding@siemens.com>
> > ---
> > drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
> > 1 file changed, 26 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> > index 8ac16808023..1da8d7aa76d 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_main.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> > @@ -1992,7 +1992,26 @@ 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)
> > +{
> > +	if (!ctx->rx_ts)
> > +		return;
> > +#ifdef CONFIG_NET_RX_BUSY_POLL
> > +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
> > +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
> > +	struct igc_inline_rx_tstamps *tstamps;
> Please move at the top of the function and add:

That would trigger a "unused variable" warning in the
CONFIG_NET_RX_BUSY_POLL case.

Btw: I was really confused that the #else statement moved to the end of
the previous line. Might someone be using a wrongly configured mail
client here?

Florian

> Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com
> 
> > +
> > +	tstamps = ctx->rx_ts;
> > +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
> > +							   tstamps->timer0);
> > +#endif
> > +}
> > +

[snip]

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Bezdeka, Florian via Intel-wired-lan]

On Mon, 2026-06-22 at 15:26 +0000, Loktionov, Aleksandr wrote:
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> > Of Ding Meng via Intel-wired-lan
> > Sent: Monday, June 22, 2026 6:13 AM
> > To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> > Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch;
> > davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> > pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka,
> > Florian <florian.bezdeka@siemens.com>
> > Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org;
> > netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> > Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp
> > reporting when NET_RX_BUSY_POLL is disabled
> > 
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> > from the NIC no longer works as expected.
> > 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp
> > in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> > 
> > Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
> I think, because it's a fix, it needs Cc: stable@vger.kernel.org

Once we hit mainline the stable machinery will pick it up by following
the Fixes: tag. If that fails for some reason we can ping stable
manually.

Florian

> 
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> 
> > Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Ding Meng <meng.ding@siemens.com>
> > ---
> > 

[snip]

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Bezdeka, Florian]

On Mon, 2026-06-22 at 15:26 +0000, Loktionov, Aleksandr wrote:
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> > Of Ding Meng via Intel-wired-lan
> > Sent: Monday, June 22, 2026 6:13 AM
> > To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> > Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch;
> > davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> > pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka,
> > Florian <florian.bezdeka@siemens.com>
> > Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org;
> > netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
> > Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp
> > reporting when NET_RX_BUSY_POLL is disabled
> > 
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> > from the NIC no longer works as expected.
> > 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp
> > in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> > 
> > Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
> I think, because it's a fix, it needs Cc: stable@vger.kernel.org

Once we hit mainline the stable machinery will pick it up by following
the Fixes: tag. If that fails for some reason we can ping stable
manually.

Florian

> 
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> 
> > Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
> > Signed-off-by: Ding Meng <meng.ding@siemens.com>
> > ---
> > 

[snip]

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Ding Meng]

Dear Paul,

Thanks for your comments.

On Mon, Jun 22, 2026 at 05:59:53PM +0200, Paul Menzel wrote: 
> Am 22.06.26 um 06:13 schrieb Ding Meng via Intel-wired-lan:
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> > from the NIC no longer works as expected.
> 
> Maybe paste some logs/errors, so it can be easier found by people with the
> same issue.

Will do.
 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp
> > in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> 
> Maybe detail, why the adapter needs to be passed now.
> 
> Also, please describe a test case to check the change.

Will do.

> > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> > index 8ac16808023..1da8d7aa76d 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_main.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> > @@ -1992,7 +1992,26 @@ 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)
> > +{
> > +	if (!ctx->rx_ts)
> > +		return;
> > +#ifdef CONFIG_NET_RX_BUSY_POLL
> 
> Is there a way to do this in C instead of the pre-processor. That way all
> the code gets build tested. (Is there a config with disabled
> NET_RX_BUSY_POLL?)
> 
 
How about defining a function to replace the pre-processor:

static inline bool is_net_rx_busy_poll()
{
#ifdef CONFIG_NET_RX_BUSY_POLL
        return true;
#else
        return false;
#endif
}

CONFIG_PREEMPT_RT=y && CONFIG_NETCONSOLE=y will cause NET_RX_BUSY_POLL
disabled.


Kind regards,
 
Ding Meng

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Ding Meng via Intel-wired-lan]

Dear Paul,

Thanks for your comments.

On Mon, Jun 22, 2026 at 05:59:53PM +0200, Paul Menzel wrote: 
> Am 22.06.26 um 06:13 schrieb Ding Meng via Intel-wired-lan:
> > When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps
> > from the NIC no longer works as expected.
> 
> Maybe paste some logs/errors, so it can be easier found by people with the
> same issue.

Will do.
 
> > 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.
> > 
> > Fix this by populating the hwtstamp field with the correct timestamp
> > in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
> 
> Maybe detail, why the adapter needs to be passed now.
> 
> Also, please describe a test case to check the change.

Will do.

> > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> > index 8ac16808023..1da8d7aa76d 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_main.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> > @@ -1992,7 +1992,26 @@ 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)
> > +{
> > +	if (!ctx->rx_ts)
> > +		return;
> > +#ifdef CONFIG_NET_RX_BUSY_POLL
> 
> Is there a way to do this in C instead of the pre-processor. That way all
> the code gets build tested. (Is there a config with disabled
> NET_RX_BUSY_POLL?)
> 
 
How about defining a function to replace the pre-processor:

static inline bool is_net_rx_busy_poll()
{
#ifdef CONFIG_NET_RX_BUSY_POLL
        return true;
#else
        return false;
#endif
}

CONFIG_PREEMPT_RT=y && CONFIG_NETCONSOLE=y will cause NET_RX_BUSY_POLL
disabled.


Kind regards,
 
Ding Meng

Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled

[Marcin Szycik]

On 24/06/2026 11:05, Florian Bezdeka via Intel-wired-lan wrote:
> On Tue, 2026-06-23 at 09:46 +0000, Kwapulinski, Piotr wrote:
>>> -----Original Message-----
>>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Ding Meng via Intel-wired-lan
>>> Sent: Monday, June 22, 2026 6:13 AM
>>> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Kiszka, Jan <jan.kiszka@siemens.com>; Bezdeka, Florian <florian.bezdeka@siemens.com>
>>> Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org; meng.ding@siemens.com; wq.wang@siemens.com
>>> Subject: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
>>>
>>> When CONFIG_NET_RX_BUSY_POLL is deactivated, fetching RX HW timestamps from the NIC no longer works as expected.
>>>
>>> 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.
>>>
>>> Fix this by populating the hwtstamp field with the correct timestamp in the default timer when CONFIG_NET_RX_BUSY_POLL is disabled.
>>>
>>> Fixes: 069b142f5819 ("igc: Add support for PTP .getcyclesx64()")
>>> Co-developed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>>> Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>>> Signed-off-by: Ding Meng <meng.ding@siemens.com>
>>> ---
>>> drivers/net/ethernet/intel/igc/igc_main.c | 38 ++++++++++++++++-------
>>> 1 file changed, 26 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
>>> index 8ac16808023..1da8d7aa76d 100644
>>> --- a/drivers/net/ethernet/intel/igc/igc_main.c
>>> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
>>> @@ -1992,7 +1992,26 @@ 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)
>>> +{
>>> +	if (!ctx->rx_ts)
>>> +		return;
>>> +#ifdef CONFIG_NET_RX_BUSY_POLL
>>> +	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
>>> +	skb_hwtstamps(skb)->netdev_data = ctx->rx_ts; #else
>>> +	struct igc_inline_rx_tstamps *tstamps;
>> Please move at the top of the function and add:
> 
> That would trigger a "unused variable" warning in the
> CONFIG_NET_RX_BUSY_POLL case.

Put it under #ifndef CONFIG_NET_RX_BUSY_POLL. Variable declarations
need to be on top.

Thanks,
Marcin

> Btw: I was really confused that the #else statement moved to the end of
> the previous line. Might someone be using a wrongly configured mail
> client here?
> 
> Florian
> 
>> Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com
>>
>>> +
>>> +	tstamps = ctx->rx_ts;
>>> +	skb_hwtstamps(skb)->hwtstamp = igc_ptp_rx_pktstamp(adapter,
>>> +							   tstamps->timer0);
>>> +#endif
>>> +}
>>> +
> 
> [snip]