diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c index 4e10ced736db..d96cdccdc1e1 100644 --- a/drivers/net/ethernet/intel/igc/igc_ptp.c +++ b/drivers/net/ethernet/intel/igc/igc_ptp.c @@ -356,16 +356,35 @@ static int igc_ptp_feature_enable_i225(struct ptp_clock_info *ptp, tsim &= ~IGC_TSICR_TT0; } if (on) { + struct timespec64 safe_start; int i = rq->perout.index; igc_pin_perout(igc, i, pin, use_freq); - igc->perout[i].start.tv_sec = rq->perout.start.sec; + igc_ptp_read(igc, &safe_start); + + /* PPS output start time is triggered by Target time(TT) + * register. Programming any past time value into TT + * register will cause PPS to never start. Need to make + * sure we program the TT register a time ahead in + * future. There isn't a stringent need to fire PPS out + * right away. Adding +2 seconds should take care of + * corner cases. Let's say if the SYSTIML is close to + * wrap up and the timer keeps ticking as we program the + * register, adding +2seconds is safe bet. + */ + safe_start.tv_sec += 2; + + if (rq->perout.start.sec < safe_start.tv_sec) + igc->perout[i].start.tv_sec = safe_start.tv_sec; + else + igc->perout[i].start.tv_sec = rq->perout.start.sec; igc->perout[i].start.tv_nsec = rq->perout.start.nsec; igc->perout[i].period.tv_sec = ts.tv_sec; igc->perout[i].period.tv_nsec = ts.tv_nsec; - wr32(trgttimh, rq->perout.start.sec); + wr32(trgttimh, (u32)igc->perout[i].start.tv_sec); /* For now, always select timer 0 as source. */ - wr32(trgttiml, rq->perout.start.nsec | IGC_TT_IO_TIMER_SEL_SYSTIM0); + wr32(trgttiml, (u32)(igc->perout[i].start.tv_nsec | + IGC_TT_IO_TIMER_SEL_SYSTIM0)); if (use_freq) wr32(freqout, ns); tsauxc |= tsauxc_mask;