* RE: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-22 4:13 [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled Ding Meng
@ 2026-06-22 15:26 ` Loktionov, Aleksandr
2026-06-24 9:12 ` Bezdeka, Florian
2026-06-22 15:59 ` Paul Menzel
2026-06-23 9:46 ` Kwapulinski, Piotr
2 siblings, 1 reply; 8+ messages in thread
From: Loktionov, Aleksandr @ 2026-06-22 15:26 UTC (permalink / raw)
To: Ding Meng, Nguyen, Anthony L, Kitszel, Przemyslaw,
andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, Kiszka, Jan, Bezdeka, Florian
Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, wq.wang@siemens.com
> -----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
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-22 15:26 ` Loktionov, Aleksandr
@ 2026-06-24 9:12 ` Bezdeka, Florian
0 siblings, 0 replies; 8+ messages in thread
From: Bezdeka, Florian @ 2026-06-24 9:12 UTC (permalink / raw)
To: andrew+netdev@lunn.ch, davem@davemloft.net,
przemyslaw.kitszel@intel.com, aleksandr.loktionov@intel.com,
Ding, Meng, kuba@kernel.org, edumazet@google.com,
anthony.l.nguyen@intel.com, Kiszka, Jan, pabeni@redhat.com
Cc: linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org,
Wang, Qi, netdev@vger.kernel.org
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]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-22 4:13 [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled Ding Meng
2026-06-22 15:26 ` Loktionov, Aleksandr
@ 2026-06-22 15:59 ` Paul Menzel
2026-06-25 10:33 ` Ding Meng
2026-06-23 9:46 ` Kwapulinski, Piotr
2 siblings, 1 reply; 8+ messages in thread
From: Paul Menzel @ 2026-06-22 15:59 UTC (permalink / raw)
To: Ding Meng, Florian Bezdeka
Cc: anthony.l.nguyen, przemyslaw.kitszel, andrew+netdev, davem,
edumazet, kuba, pabeni, jan.kiszka, intel-wired-lan, linux-kernel,
netdev, wq.wang
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
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-22 15:59 ` Paul Menzel
@ 2026-06-25 10:33 ` Ding Meng
0 siblings, 0 replies; 8+ messages in thread
From: Ding Meng @ 2026-06-25 10:33 UTC (permalink / raw)
To: Paul Menzel
Cc: Florian Bezdeka, anthony.l.nguyen, przemyslaw.kitszel,
andrew+netdev, davem, edumazet, kuba, pabeni, jan.kiszka,
intel-wired-lan, linux-kernel, netdev, wq.wang
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
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-22 4:13 [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled Ding Meng
2026-06-22 15:26 ` Loktionov, Aleksandr
2026-06-22 15:59 ` Paul Menzel
@ 2026-06-23 9:46 ` Kwapulinski, Piotr
2026-06-24 9:05 ` Florian Bezdeka
2 siblings, 1 reply; 8+ messages in thread
From: Kwapulinski, Piotr @ 2026-06-23 9:46 UTC (permalink / raw)
To: Ding Meng, Nguyen, Anthony L, Kitszel, Przemyslaw,
andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, Kiszka, Jan, Bezdeka, Florian
Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, wq.wang@siemens.com
>-----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
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-23 9:46 ` Kwapulinski, Piotr
@ 2026-06-24 9:05 ` Florian Bezdeka
2026-06-25 11:07 ` Marcin Szycik
0 siblings, 1 reply; 8+ messages in thread
From: Florian Bezdeka @ 2026-06-24 9:05 UTC (permalink / raw)
To: Kwapulinski, Piotr, Ding Meng, Nguyen, Anthony L,
Kitszel, Przemyslaw, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
Kiszka, Jan
Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, wq.wang@siemens.com
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]
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Intel-wired-lan] [PATCH net] igc: Fix RX HW timestamp reporting when NET_RX_BUSY_POLL is disabled
2026-06-24 9:05 ` Florian Bezdeka
@ 2026-06-25 11:07 ` Marcin Szycik
0 siblings, 0 replies; 8+ messages in thread
From: Marcin Szycik @ 2026-06-25 11:07 UTC (permalink / raw)
To: Florian Bezdeka, Kwapulinski, Piotr, Ding Meng, Nguyen, Anthony L,
Kitszel, Przemyslaw, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
Kiszka, Jan
Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, wq.wang@siemens.com
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]
^ permalink raw reply [flat|nested] 8+ messages in thread