From: Vinicius Costa Gomes vinicius.gomes@intel.com
[ Upstream commit ee14cc9ea19ba9678177e2224a9c58cce5937c73 ]
Fix "double" clearing of interrupts, which can cause external events or timestamps to be missed.
The E1000_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 E1000_TSIRC into 'tsicr'; 2. handle the interrupts present into 'tsirc' and mark them in 'ack'; 3. write 'ack' into E1000_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: 00c65578b47b ("igb: enable internal PPS for the i210") Acked-by: Richard Cochran richardcochran@gmail.com Signed-off-by: Vinicius Costa Gomes vinicius.gomes@intel.com Tested-by: Pucha Himasekhar Reddy himasekharx.reddy.pucha@intel.com (A Contingent worker at Intel) Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/igb/igb_main.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 45ce4ed16146e..81d9a5338be5e 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -6926,44 +6926,31 @@ static void igb_extts(struct igb_adapter *adapter, int tsintr_tt) static void igb_tsync_interrupt(struct igb_adapter *adapter) { struct e1000_hw *hw = &adapter->hw; - u32 ack = 0, tsicr = rd32(E1000_TSICR); + u32 tsicr = rd32(E1000_TSICR); struct ptp_clock_event event;
if (tsicr & TSINTR_SYS_WRAP) { event.type = PTP_CLOCK_PPS; if (adapter->ptp_caps.pps) ptp_clock_event(adapter->ptp_clock, &event); - ack |= TSINTR_SYS_WRAP; }
if (tsicr & E1000_TSICR_TXTS) { /* retrieve hardware timestamp */ schedule_work(&adapter->ptp_tx_work); - ack |= E1000_TSICR_TXTS; }
- if (tsicr & TSINTR_TT0) { + if (tsicr & TSINTR_TT0) igb_perout(adapter, 0); - ack |= TSINTR_TT0; - }
- if (tsicr & TSINTR_TT1) { + if (tsicr & TSINTR_TT1) igb_perout(adapter, 1); - ack |= TSINTR_TT1; - }
- if (tsicr & TSINTR_AUTT0) { + if (tsicr & TSINTR_AUTT0) igb_extts(adapter, 0); - ack |= TSINTR_AUTT0; - }
- if (tsicr & TSINTR_AUTT1) { + if (tsicr & TSINTR_AUTT1) igb_extts(adapter, 1); - ack |= TSINTR_AUTT1; - } - - /* acknowledge the interrupts */ - wr32(E1000_TSICR, ack); }
static irqreturn_t igb_msix_other(int irq, void *data)