STRUCT EF4_CHANNEL(9)

💖 NAME 💖

okay bestie, welcome to the Kernel API Manual page for struct ef4_channel(9) — it’s literally “An Efx channel,” and we’re about to read it like a very organized group chat.

---

✨ SYNOPSIS ✨

Here’s the exact struct, no cap — copy it exactly, do not retype it from vibe:

       struct ef4_channel {
           struct ef4_nic *efx;
           int channel;
           const struct ef4_channel_type *type;
           bool eventq_init;
           bool enabled;
           int irq;
           unsigned int irq_moderation_us;
           struct net_device *napi_dev;
           struct napi_struct napi_str;
         #ifdef CONFIG_NET_RX_BUSY_POLL;
           unsigned long busy_poll_state;
         #endif;
           struct ef4_special_buffer eventq;
           unsigned int eventq_mask;
           unsigned int eventq_read_ptr;
           int event_test_cpu;
           unsigned int irq_count;
           unsigned int irq_mod_score;
         #ifdef CONFIG_RFS_ACCEL;
           unsigned int rfs_filters_added;
         #define RPS_FLOW_ID_INVALID 0xFFFFFFFF;
           u32 *rps_flow_id;
         #endif;
           unsigned n_rx_tobe_disc;
           unsigned n_rx_ip_hdr_chksum_err;
           unsigned n_rx_tcp_udp_chksum_err;
           unsigned n_rx_mcast_mismatch;
           unsigned n_rx_frm_trunc;
           unsigned n_rx_overlength;
           unsigned n_skbuff_leaks;
           unsigned int n_rx_nodesc_trunc;
           unsigned int n_rx_merge_events;
           unsigned int n_rx_merge_packets;
           unsigned int rx_pkt_n_frags;
           unsigned int rx_pkt_index;
           struct ef4_rx_queue rx_queue;
           struct ef4_tx_queue tx_queue[EF4_TXQ_TYPES];
        };

---

🎀 Members 🎀

Let’s go through every single member, in order, so nothing gets left on read:

• efx — the associated Efx NIC.
• channel — the channel instance number.
• type — the channel type definition.
• eventq_init — event queue initialised flag.
• enabled — channel enabled indicator.
• irq — IRQ number, and yes: MSI and MSI-X only.
• irq_moderation_us — IRQ moderation value, in microseconds.
• napi_dev — net device used with NAPI.
• napi_str — NAPI control structure.
• eventq — event queue buffer.
• eventq_mask — event queue pointer mask.
• eventq_read_ptr — event queue read pointer.
• event_test_cpu — last CPU to handle interrupt or test event for this channel.
• irq_count — number of IRQs since last adaptive moderation decision.
• irq_mod_score — IRQ moderation score.
• rps_flow_id — flow IDs of filters allocated for accelerated RFS, indexed by filter ID.
• n_rx_tobe_disc — count of RX_TOBE_DISC errors.
• n_rx_ip_hdr_chksum_err — count of RX IP header checksum errors.
• n_rx_tcp_udp_chksum_err — count of RX TCP and UDP checksum errors.
• n_rx_mcast_mismatch — count of unmatched multicast frames.
• n_rx_frm_trunc — count of RX_FRM_TRUNC errors.
• n_rx_overlength — count of RX_OVERLENGTH errors.
• n_skbuff_leaks — count of skbuffs leaked due to RX overrun.
• n_rx_nodesc_trunc — number of RX packets truncated and then dropped due to lack of descriptors.
• n_rx_merge_events — number of RX merged completion events.
• n_rx_merge_packets — number of RX packets completed by merged events.
• rx_pkt_n_frags — number of fragments in next packet to be delivered by __ef4_rx_packet, or zero if there is none.
• rx_pkt_index — ring index of first buffer for next packet to be delivered by __ef4_rx_packet, if rx_pkt_n_frags != 0.
• rx_queue — RX queue for this channel.
• tx_queue — TX queues for this channel.

---

🌈 Description 🌈

A channel comprises an event queue, at least one TX queue, at least one RX queue, and an associated tasklet for processing the event queue. That’s the whole bundle, bestie — event queue, TX queue(s), RX queue(s), and the tasklet doing the event-queue processing. 💅

---

👑 SEE ALSO 👑

Kernel file: ./drivers/net/ethernet/sfc/falcon/net_driver.h

The page also points you at these icons:

• struct ef4_buffer(9)
• struct ef4_special_buffer(9)
• struct ef4_tx_buffer(9)
• struct ef4_tx_queue(9)
• struct ef4_rx_buffer(9)
• struct ef4_rx_page_state(9)
• struct ef4_rx_queue(9)
• struct ef4_msi_context(9)
• struct ef4_channel_type(9)
• struct ef4_link_state(9)
• struct ef4_phy_operations(9)
• enum ef4_phy_mode(9)
• struct ef4_hw_stat_desc(9)
• struct ef4_nic(9)
• struct ef4_nic_type(9)

---

Signed with sparkle from the source path ./drivers/net/ethernet/sfc/falcon — October 2026 edition — that’s the source/version + date vibe for this struct ef4_channel(9) page, mwah 💋✨