RE: [PATCH v2] igb: Fix extts capture value format for 82580/i354/i350

[Keller, Jacob E]

> -----Original Message-----
> From: Yuezhen Luan <eggcar.luan@xxxxxxxxx>
> Sent: Thursday, June 1, 2023 12:01 AM
> To: Brandeburg, Jesse <jesse.brandeburg@xxxxxxxxx>; Nguyen, Anthony L
> <anthony.l.nguyen@xxxxxxxxx>; davem@xxxxxxxxxxxxx;
> edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx
> Cc: intel-wired-lan@xxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Keller, Jacob E <jacob.e.keller@xxxxxxxxx>; Yuezhen
> Luan <eggcar.luan@xxxxxxxxx>
> Subject: [PATCH v2] igb: Fix extts capture value format for 82580/i354/i350
> 
> 82580/i354/i350 features circle-counter-like timestamp registers
> that are different with newer i210. The EXTTS capture value in
> AUXTSMPx should be converted from raw circle counter value to
> timestamp value in resolution of 1 nanosec by the driver.
> 
> This issue can be reproduced on i350 nics, connecting an 1PPS
> signal to a SDP pin, and run 'ts2phc' command to read external
> 1PPS timestamp value. On i210 this works fine, but on i350 the
> extts is not correctly converted.
> 
> The i350/i354/82580's SYSTIM and other timestamp registers are
> 40bit counters, presenting time range of 2^40 ns, that means these
> registers overflows every about 1099s. This causes all these regs
> can't be used directly in contrast to the newer i210/i211s.
> 
> The igb driver needs to convert these raw register values to
> valid time stamp format by using kernel timecounter apis for i350s
> families. Here the igb_extts() just forgot to do the convert.
> 
> Signed-off-by: Yuezhen Luan <eggcar.luan@xxxxxxxxx>

Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>	

Thanks for fixing this!

@Nguyen, Anthony L
I think this is a worthy net fix.

> ---
>  drivers/net/ethernet/intel/igb/igb_main.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index 58872a4c2..bb3db387d 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -6947,6 +6947,7 @@ static void igb_extts(struct igb_adapter *adapter, int
> tsintr_tt)
>  	struct e1000_hw *hw = &adapter->hw;
>  	struct ptp_clock_event event;
>  	struct timespec64 ts;
> +	unsigned long flags;
> 
>  	if (pin < 0 || pin >= IGB_N_SDP)
>  		return;
> @@ -6954,9 +6955,12 @@ static void igb_extts(struct igb_adapter *adapter, int
> tsintr_tt)
>  	if (hw->mac.type == e1000_82580 ||
>  	    hw->mac.type == e1000_i354 ||
>  	    hw->mac.type == e1000_i350) {
> -		s64 ns = rd32(auxstmpl);
> +		u64 ns = rd32(auxstmpl);
> 
> -		ns += ((s64)(rd32(auxstmph) & 0xFF)) << 32;
> +		ns += ((u64)(rd32(auxstmph) & 0xFF)) << 32;
> +		spin_lock_irqsave(&adapter->tmreg_lock, flags);
> +		ns = timecounter_cyc2time(&adapter->tc, ns);
> +		spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
>  		ts = ns_to_timespec64(ns);
>  	} else {
>  		ts.tv_nsec = rd32(auxstmpl);
> --
> 2.34.1