From c37da859c4962506c4ba64374716c22c2c585542 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Tue, 13 Feb 2024 11:51:57 -0800 Subject: [PATCH] igc: Fix missing time sync events Fix "double" clearing of interrupts, which can cause external events or timestamps to be missed. The IGC_TSIRC Time Sync Interrupt Cause register can be cleared in two ways, by either reading it or by writing '1' into the specific cause bit. This is documented in section 8.16.1. The following flow was used: 1. read IGC_TSIRC into 'tsicr'; 2. handle the interrupts present in 'tsirc' and mark them in 'ack'; 3. write 'ack' into IGC_TSICR; As both (1) and (3) will clear the interrupt cause, if the same interrupt happens again between (1) and (3) it will be ignored, causing events to be missed. Remove the extra clear in (3). Fixes: 2c344ae24501 ("igc: Add support for TX timestamping") Reviewed-by: Kurt Kanzenbach Tested-by: Kurt Kanzenbach # Intel i225 Signed-off-by: Vinicius Costa Gomes --- drivers/net/ethernet/intel/igc/igc_main.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 0f8d112cb774..fdcfb5184283 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -5443,25 +5443,22 @@ igc_features_check(struct sk_buff *skb, struct net_device *dev, static void igc_tsync_interrupt(struct igc_adapter *adapter) { - u32 ack, tsauxc, sec, nsec, tsicr; struct igc_hw *hw = &adapter->hw; + u32 tsauxc, sec, nsec, tsicr; struct ptp_clock_event event; struct timespec64 ts; tsicr = rd32(IGC_TSICR); - ack = 0; if (tsicr & IGC_TSICR_SYS_WRAP) { event.type = PTP_CLOCK_PPS; if (adapter->ptp_caps.pps) ptp_clock_event(adapter->ptp_clock, &event); - ack |= IGC_TSICR_SYS_WRAP; } if (tsicr & IGC_TSICR_TXTS) { /* retrieve hardware timestamp */ schedule_work(&adapter->ptp_tx_work); - ack |= IGC_TSICR_TXTS; } if (tsicr & IGC_TSICR_TT0) { @@ -5475,7 +5472,6 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter) wr32(IGC_TSAUXC, tsauxc); adapter->perout[0].start = ts; spin_unlock(&adapter->tmreg_lock); - ack |= IGC_TSICR_TT0; } if (tsicr & IGC_TSICR_TT1) { @@ -5489,7 +5485,6 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter) wr32(IGC_TSAUXC, tsauxc); adapter->perout[1].start = ts; spin_unlock(&adapter->tmreg_lock); - ack |= IGC_TSICR_TT1; } if (tsicr & IGC_TSICR_AUTT0) { @@ -5499,7 +5494,6 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter) event.index = 0; event.timestamp = sec * NSEC_PER_SEC + nsec; ptp_clock_event(adapter->ptp_clock, &event); - ack |= IGC_TSICR_AUTT0; } if (tsicr & IGC_TSICR_AUTT1) { @@ -5509,11 +5503,7 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter) event.index = 1; event.timestamp = sec * NSEC_PER_SEC + nsec; ptp_clock_event(adapter->ptp_clock, &event); - ack |= IGC_TSICR_AUTT1; } - - /* acknowledge the interrupts */ - wr32(IGC_TSICR, ack); } /**