[Intel-wired-lan] [PATCH iwl-net v11] igc: Fix trigger of incorrect irq in igc_xsk_wakeup function

[Intel-wired-lan] [PATCH iwl-net v11] igc: Fix trigger of incorrect irq in igc_xsk_wakeup function

[Vivek Behera via Intel-wired-lan]

This patch addresses the issue where the igc_xsk_wakeup function
was triggering an incorrect IRQ for tx-0 when the i226 is configured
with only 2 combined queues or in an environment with 2 active CPU cores.
This prevented XDP Zero-copy send functionality in such split IRQ
configurations.

The fix implements the correct logic for extracting q_vectors saved
during rx and tx ring allocation and utilizes flags provided by the
ndo_xsk_wakeup API to trigger the appropriate IRQ.

Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
Fixes: 15fd021bc427 ("igc: Add Tx hardware timestamp request for AF_XDP zero-copy packet")
Signed-off-by: Vivek Behera <vivek.behera@siemens.com>
Reviewed-by: Jacob Keller <jacob.keller@intel.com>
Reviewed-by: Aleksandr loktinov <aleksandr.loktionov@intel.com>
Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com>
---
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v6: https://lore.kernel.org/intel-wired-lan/20251211173916.23951-1-vivek.behera@siemens.com/
v7: https://lore.kernel.org/intel-wired-lan/20251212163208.137164-1-vivek.behera@siemens.com/
v8: https://lore.kernel.org/intel-wired-lan/20251215122052.412327-1-vivek.behera@siemens.com/
v9: https://lore.kernel.org/intel-wired-lan/20251220110009.137245-1-vivek.behera@siemens.com/
v10: https://lore.kernel.org/intel-wired-lan/20260117150753.2088857-1-vivek.behera@siemens.com/
changelog:
v1
- Inital description of the Bug and steps to reproduce with RTC Testbench
- Test results after applying the patch
v1 -> v2
- Handling of RX and TX Wakeup in igc_xsk_wakeup for a split IRQ configuration
- Removal of igc_trigger_rxtxq_interrupt (now redundant)
- Added flag to igc_xsk_wakeup function call in igc_ptp_free_tx_buffer
v2 -> v3
- Added 'Fixes:' tags for the relevant commits.
- Added reviewer
v3 -> v4
- Added reviewer
v4 -> v5
- Updated comment style from multi-star to standard linux convention
v5 -> v6
- Resolve formatting issues highlighted by reviewers
- Try to include version histroy as defined in netdev guidelines
- Included review suggestions from Przemyslaw
- Added reviewers
v6 -> v7
- Included review suggestions from Przemyslaw missed in v6
v7 -> v8
- Modified sequence to complete all error checks for rx and tx
  before updating napi states and triggering irq
v8 -> v9
- Included review feedback and suggestions from Tony and Siang
v9 -> v10
- Introduced a simplified logic for sequential check for RX and TX
v10 -> v11
- Improved explanation of implemented logic in comment block
---
 drivers/net/ethernet/intel/igc/igc_main.c | 34 ++++++++++++++++-------
 drivers/net/ethernet/intel/igc/igc_ptp.c  |  3 +-
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 7aafa60ba0c8..0a2673cf7ece 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6908,28 +6908,29 @@ static int igc_xdp_xmit(struct net_device *dev, int num_frames,
 	return nxmit;
 }
 
-static void igc_trigger_rxtxq_interrupt(struct igc_adapter *adapter,
-					struct igc_q_vector *q_vector)
+static u32 igc_sw_irq_prep(struct igc_q_vector *q_vector)
 {
-	struct igc_hw *hw = &adapter->hw;
 	u32 eics = 0;
 
-	eics |= q_vector->eims_value;
-	wr32(IGC_EICS, eics);
+	if (!napi_if_scheduled_mark_missed(&q_vector->napi))
+		eics = q_vector->eims_value;
+
+	return eics;
 }
 
 int igc_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
 {
 	struct igc_adapter *adapter = netdev_priv(dev);
-	struct igc_q_vector *q_vector;
+	struct igc_hw *hw = &adapter->hw;
 	struct igc_ring *ring;
+	u32 eics = 0;
 
 	if (test_bit(__IGC_DOWN, &adapter->state))
 		return -ENETDOWN;
 
 	if (!igc_xdp_is_enabled(adapter))
 		return -ENXIO;
-
+	/* Check if queue_id is valid. Tx and Rx queue numbers are always same */
 	if (queue_id >= adapter->num_rx_queues)
 		return -EINVAL;
 
@@ -6938,9 +6939,22 @@ int igc_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
 	if (!ring->xsk_pool)
 		return -ENXIO;
 
-	q_vector = adapter->q_vector[queue_id];
-	if (!napi_if_scheduled_mark_missed(&q_vector->napi))
-		igc_trigger_rxtxq_interrupt(adapter, q_vector);
+	if (flags & XDP_WAKEUP_RX)
+		eics |= igc_sw_irq_prep(ring->q_vector);
+
+	if (flags & XDP_WAKEUP_TX) {
+		/* If IGC_FLAG_QUEUE_PAIRS is active, the q_vector
+		 * and NAPI is shared between RX and TX.
+		 * If NAPI is already running it would be marked as missed
+		 * from the RX path, making this TX call a NOP
+		 */
+		ring = adapter->tx_ring[queue_id];
+		eics |= igc_sw_irq_prep(ring->q_vector);
+	}
+
+	if (eics)
+		/* Cause software interrupt */
+		wr32(IGC_EICS, eics);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index b7b46d863bee..df2e500a4d7e 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -550,7 +550,8 @@ static void igc_ptp_free_tx_buffer(struct igc_adapter *adapter,
 		tstamp->buffer_type = 0;
 
 		/* Trigger txrx interrupt for transmit completion */
-		igc_xsk_wakeup(adapter->netdev, tstamp->xsk_queue_index, 0);
+		igc_xsk_wakeup(adapter->netdev, tstamp->xsk_queue_index,
+			       XDP_WAKEUP_TX);
 
 		return;
 	}
-- 
2.34.1

Re: [Intel-wired-lan] [PATCH iwl-net v11] igc: Fix trigger of incorrect irq in igc_xsk_wakeup function

[Song, Yoong Siang]

On Tuesday, January 20, 2026 3:52 PM, Vivek Behera <vivek.behera@siemens.com> wrote:
>This patch addresses the issue where the igc_xsk_wakeup function
>was triggering an incorrect IRQ for tx-0 when the i226 is configured
>with only 2 combined queues or in an environment with 2 active CPU cores.
>This prevented XDP Zero-copy send functionality in such split IRQ
>configurations.
>
>The fix implements the correct logic for extracting q_vectors saved
>during rx and tx ring allocation and utilizes flags provided by the
>ndo_xsk_wakeup API to trigger the appropriate IRQ.
>
>Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
>Fixes: 15fd021bc427 ("igc: Add Tx hardware timestamp request for AF_XDP
>zero-copy packet")
>Signed-off-by: Vivek Behera <vivek.behera@siemens.com>
>Reviewed-by: Jacob Keller <jacob.keller@intel.com>
>Reviewed-by: Aleksandr loktinov <aleksandr.loktionov@intel.com>
>Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com>

Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>

Re: [Intel-wired-lan] [PATCH iwl-net v11] igc: Fix trigger of incorrect irq in igc_xsk_wakeup function

[Dahan, AvigailX]

[-- Attachment #1: Type: text/plain, Size: 3485 bytes --]


On 20/01/2026 9:52, Vivek Behera via Intel-wired-lan wrote:
> This patch addresses the issue where the igc_xsk_wakeup function
> was triggering an incorrect IRQ for tx-0 when the i226 is configured
> with only 2 combined queues or in an environment with 2 active CPU cores.
> This prevented XDP Zero-copy send functionality in such split IRQ
> configurations.
>
> The fix implements the correct logic for extracting q_vectors saved
> during rx and tx ring allocation and utilizes flags provided by the
> ndo_xsk_wakeup API to trigger the appropriate IRQ.
>
> Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
> Fixes: 15fd021bc427 ("igc: Add Tx hardware timestamp request for AF_XDP zero-copy packet")
> Signed-off-by: Vivek Behera<vivek.behera@siemens.com>
> Reviewed-by: Jacob Keller<jacob.keller@intel.com>
> Reviewed-by: Aleksandr loktinov<aleksandr.loktionov@intel.com>
> Reviewed-by: Piotr Kwapulinski<piotr.kwapulinski@intel.com>
> ---
> v1:https://lore.kernel.org/intel-wired-lan/AS1PR10MB5392B7268416DB8A1624FDB88FA7A@AS1PR10MB5392.EURPRD10.PROD.OUTLOOK.COM/
> v2:https://lore.kernel.org/intel-wired-lan/AS1PR10MB539280B1427DA0ABE9D65E628FA5A@AS1PR10MB5392.EURPRD10.PROD.OUTLOOK.COM/
> v3:https://lore.kernel.org/intel-wired-lan/IA3PR11MB8986E4ACB7F264CF2DD1D750E5A0A@IA3PR11MB8986.namprd11.prod.outlook.com/
> v4:https://lore.kernel.org/intel-wired-lan/AS1PR10MB53926CB955FBD4F9F4A018818FA0A@AS1PR10MB5392.EURPRD10.PROD.OUTLOOK.COM/
> v5:https://lore.kernel.org/intel-wired-lan/AS1PR10MB5392FCA415A38B9DD7BB5F218FA0A@AS1PR10MB5392.EURPRD10.PROD.OUTLOOK.COM/
> v6:https://lore.kernel.org/intel-wired-lan/20251211173916.23951-1-vivek.behera@siemens.com/
> v7:https://lore.kernel.org/intel-wired-lan/20251212163208.137164-1-vivek.behera@siemens.com/
> v8:https://lore.kernel.org/intel-wired-lan/20251215122052.412327-1-vivek.behera@siemens.com/
> v9:https://lore.kernel.org/intel-wired-lan/20251220110009.137245-1-vivek.behera@siemens.com/
> v10:https://lore.kernel.org/intel-wired-lan/20260117150753.2088857-1-vivek.behera@siemens.com/
> changelog:
> v1
> - Inital description of the Bug and steps to reproduce with RTC Testbench
> - Test results after applying the patch
> v1 -> v2
> - Handling of RX and TX Wakeup in igc_xsk_wakeup for a split IRQ configuration
> - Removal of igc_trigger_rxtxq_interrupt (now redundant)
> - Added flag to igc_xsk_wakeup function call in igc_ptp_free_tx_buffer
> v2 -> v3
> - Added 'Fixes:' tags for the relevant commits.
> - Added reviewer
> v3 -> v4
> - Added reviewer
> v4 -> v5
> - Updated comment style from multi-star to standard linux convention
> v5 -> v6
> - Resolve formatting issues highlighted by reviewers
> - Try to include version histroy as defined in netdev guidelines
> - Included review suggestions from Przemyslaw
> - Added reviewers
> v6 -> v7
> - Included review suggestions from Przemyslaw missed in v6
> v7 -> v8
> - Modified sequence to complete all error checks for rx and tx
>    before updating napi states and triggering irq
> v8 -> v9
> - Included review feedback and suggestions from Tony and Siang
> v9 -> v10
> - Introduced a simplified logic for sequential check for RX and TX
> v10 -> v11
> - Improved explanation of implemented logic in comment block
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c | 34 ++++++++++++++++-------
>   drivers/net/ethernet/intel/igc/igc_ptp.c  |  3 +-
>   2 files changed, 26 insertions(+), 11 deletions(-)
>
Tested-by: Avigail Dahan <avigailx.dahan@intel.com>

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