[PATCH iwl-net 09/12] ice: keep Tx timestamp slots tracked until completion or timeout
From: Jacob Keller <jacob.e.keller@intel.com>
Date: 2026-08-22 00:15:09
Also in:
intel-wired-lan
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Petr Oros <redacted>
When the link goes down the processing loop drops every outstanding
request, and a request whose timestamp is not ready yet is freed
without reading the PHY slot. The hardware completes the capture a
moment later, the orphaned ready bit blocks the port interrupt until
the next link-up sweep, and the freed index can meanwhile be reused
by a new request whose slot the hardware then overwrites. Captured on
a reproducer as ready bits with no in_use owner right after a link
bounce.
Stop dropping on link down. Mark the outstanding requests stale so
their completions are read and discarded, reject new requests while
the link is down, and free a not yet ready slot only after the two
second timeout. This way an index is never reused while the hardware
can still write it and never left untracked while a completion can
still arrive.
To avoid an IRQ storm in the event that we really do have a stale packet
that is not timestamped, modify ice_ptp_tx_tstamps_pending() to ignore
stale timestamps when checking for whether to re-arm the IRQ from the
miscellaneous thread function. Instead, only check for stale packets in the
auxiliary work thread. This way we do not check in a tight loop waiting for
a timestamp that may never come.
This effectively reverts commit fcc2cef37fed ("ice/ptp: fix the PTP worker
retrying indefinitely if the link went down"), which tried to release an
index before this 2 second wait period.
Fixes: fcc2cef37fed ("ice/ptp: fix the PTP worker retrying indefinitely if the link went down")
Suggested-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Petr Oros <redacted>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Maciek Machnikowski <redacted>
---
drivers/net/ethernet/intel/ice/ice_ptp.h | 8 ++++--
drivers/net/ethernet/intel/ice/ice_main.c | 2 +-
drivers/net/ethernet/intel/ice/ice_ptp.c | 44 +++++++++++++++----------------
3 files changed, 28 insertions(+), 26 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index da2003ba3bb0..13158a9319fb 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h@@ -132,6 +132,9 @@ struct ice_ptp_tx { #define INDEX_PER_PORT_E82X 16 #define INDEX_PER_PORT 64 +/* Maximum number of timestamp indexes across all devices */ +#define INDEX_PER_PORT_MAX INDEX_PER_PORT + /** * struct ice_ptp_port - data used to initialize an external port for PTP *
@@ -316,7 +319,7 @@ void ice_ptp_req_tx_single_tstamp(struct ice_ptp_tx *tx, u8 idx); void ice_ptp_complete_tx_single_tstamp(struct ice_ptp_tx *tx); void ice_ptp_process_ts(struct ice_pf *pf); irqreturn_t ice_ptp_ts_irq(struct ice_pf *pf); -bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf); +bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf, bool in_irq); u64 ice_ptp_read_src_clk_reg(struct ice_pf *pf, struct ptp_system_timestamp *sts);
@@ -364,7 +367,8 @@ static inline irqreturn_t ice_ptp_ts_irq(struct ice_pf *pf) return IRQ_HANDLED; } -static inline bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf) +static inline bool +ice_ptp_tx_tstamps_pending(struct ice_pf *pf, bool in_irq) { return false; }
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index bb631ae9e67d..c84d63b8d261 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c@@ -3248,7 +3248,7 @@ static irqreturn_t ice_misc_intr_thread_fn(int __always_unused irq, void *data) ice_irq_dynamic_ena(hw, NULL, NULL); ice_flush(hw); - if (ice_ptp_tx_tstamps_pending(pf)) { + if (ice_ptp_tx_tstamps_pending(pf, true)) { /* If any new Tx timestamps happened while in interrupt, * re-arm the interrupt to trigger it again. */
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index a049dc7a2241..1a9bf8839404 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c@@ -364,9 +364,12 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp) static bool ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx) { + struct ice_ptp_port *ptp_port = + container_of(tx, struct ice_ptp_port, tx); + lockdep_assert_held(&tx->lock); - return tx->init && !tx->calibrating; + return tx->init && !tx->calibrating && ptp_port->link_up; } /**
@@ -563,7 +566,6 @@ static void ice_ptp_process_tx_tstamp(struct ice_ptp_tx *tx) struct ice_pf *pf; struct ice_hw *hw; u64 tstamp_ready; - bool link_up; int err; u8 idx;
@@ -581,14 +583,11 @@ static void ice_ptp_process_tx_tstamp(struct ice_ptp_tx *tx) return; } - /* Drop packets if the link went down */ - link_up = ptp_port->link_up; - for_each_set_bit(idx, tx->in_use, tx->len) { struct skb_shared_hwtstamps shhwtstamps = {}; u8 phy_idx = idx + tx->offset; u64 raw_tstamp = 0, tstamp; - bool drop_ts = !link_up; + bool drop_ts = false; struct sk_buff *skb; /* Drop packets which have waited for more than 2 seconds */
@@ -1372,6 +1371,9 @@ void ice_ptp_link_change(struct ice_pf *pf, bool linkup) if (pf->hw.reset_ongoing) return; + if (!linkup) + ice_ptp_mark_tx_tracker_stale(&ptp_port->tx); + if (hw->mac_type == ICE_MAC_GENERIC_3K_E825 && test_bit(ICE_FLAG_DPLL, pf->flags)) { int pin, err;
@@ -2763,28 +2765,29 @@ void ice_ptp_process_ts(struct ice_pf *pf) } } -static bool ice_port_has_timestamps(struct ice_ptp_tx *tx) +static bool ice_port_has_timestamps(struct ice_ptp_tx *tx, bool in_irq) { - bool more_timestamps; + DECLARE_BITMAP(tstamps, INDEX_PER_PORT_MAX) = {}; scoped_guard(spinlock_irqsave, &tx->lock) { if (!tx->init) return false; - more_timestamps = !bitmap_empty(tx->in_use, tx->len); + if (in_irq) + return bitmap_andnot(tstamps, tx->in_use, tx->stale, tx->len); + else + return !bitmap_empty(tx->in_use, tx->len); } - - return more_timestamps; } -static bool ice_any_port_has_timestamps(struct ice_pf *pf) +static bool ice_any_port_has_timestamps(struct ice_pf *pf, bool in_irq) { bool have_tstamps = false; struct ice_ptp_port *port; rcu_read_lock(); list_for_each_entry_rcu(port, &pf->adapter->ports.list, list_node) { - if (ice_port_has_timestamps(&port->tx)) { + if (ice_port_has_timestamps(&port->tx, in_irq)) { have_tstamps = true; break; }
@@ -2794,7 +2797,7 @@ static bool ice_any_port_has_timestamps(struct ice_pf *pf) return have_tstamps; } -bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf) +bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf, bool in_irq) { struct ice_hw *hw = &pf->hw; int ret;
@@ -2804,11 +2807,11 @@ bool ice_ptp_tx_tstamps_pending(struct ice_pf *pf) case ICE_PTP_TX_INTERRUPT_NONE: return false; case ICE_PTP_TX_INTERRUPT_SELF: - if (ice_port_has_timestamps(&pf->ptp.port.tx)) + if (ice_port_has_timestamps(&pf->ptp.port.tx, in_irq)) return true; break; case ICE_PTP_TX_INTERRUPT_ALL: - if (ice_any_port_has_timestamps(pf)) + if (ice_any_port_has_timestamps(pf, in_irq)) return true; break; default:
@@ -2884,7 +2887,7 @@ irqreturn_t ice_ptp_ts_irq(struct ice_pf *pf) /* E830 can read timestamps in the top half using rd32() */ ice_ptp_process_ts(pf); - if (ice_ptp_tx_tstamps_pending(pf)) { + if (ice_ptp_tx_tstamps_pending(pf, true)) { /* Process outstanding Tx timestamps. If there * is more work, re-arm the interrupt to trigger again. */
@@ -2914,7 +2917,6 @@ static void ice_ptp_maybe_trigger_tx_interrupt(struct ice_pf *pf) { struct device *dev = ice_pf_to_dev(pf); struct ice_hw *hw = &pf->hw; - int ret; if (!pf->ptp.port.tx.has_ready_bitmap) return;
@@ -2922,11 +2924,7 @@ static void ice_ptp_maybe_trigger_tx_interrupt(struct ice_pf *pf) if (!ice_pf_src_tmr_owned(pf)) return; - ret = ice_check_phy_tx_tstamp_ready(hw); - if (ret < 0) { - dev_dbg(dev, "PTP periodic task unable to read PHY timestamp ready bitmap, err %d\n", - ret); - } else if (ret) { + if (ice_ptp_tx_tstamps_pending(pf, false)) { dev_dbg(dev, "PTP periodic task detected waiting timestamps. Triggering Tx timestamp interrupt now.\n"); wr32(hw, PFINT_OICR, PFINT_OICR_TSYN_TX_M);
--
2.55.0.814.gc42f45431d0f