From: Vinicius Costa Gomes vinicius.gomes@intel.com
[ Upstream commit 244ae992e3e80e5c9c272c77324c831148457f95 ]
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 kurt@linutronix.de Tested-by: Kurt Kanzenbach kurt@linutronix.de # Intel i225 Signed-off-by: Vinicius Costa Gomes vinicius.gomes@intel.com Tested-by: Naama Meir naamax.meir@linux.intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 e549ffca88e39..fc1de116d5548 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -5304,25 +5304,22 @@ 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 */ igc_ptp_tx_tstamp_event(adapter); - ack |= IGC_TSICR_TXTS; }
if (tsicr & IGC_TSICR_TT0) { @@ -5336,7 +5333,6 @@ 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) { @@ -5350,7 +5346,6 @@ 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) { @@ -5360,7 +5355,6 @@ 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) { @@ -5370,11 +5364,7 @@ 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); }
/**