> -----Original Message-----
> From: Michal Swiatkowski <[email protected]>
> Sent: Monday, March 10, 2025 11:04 PM
> To: Keller, Jacob E <[email protected]>
> Cc: Nguyen, Anthony L <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; Andrew Lunn <[email protected]>; David
> S. Miller <[email protected]>; Eric Dumazet <[email protected]>;
> Jakub Kicinski <[email protected]>; Paolo Abeni <[email protected]>; Richard
> Cochran <[email protected]>; Ruud Bos <[email protected]>; Paul
> Barker <[email protected]>; Niklas Söderlund
> <[email protected]>; Bryan Whitehead
> <[email protected]>; [email protected]; Raju
> Lakkaraju <[email protected]>; Florian Fainelli
> <[email protected]>; Broadcom internal kernel review list <bcm-
> [email protected]>; Andrew Lunn <[email protected]>; Heiner
> Kallweit <[email protected]>; Russell King <[email protected]>;
> Jonathan Lemon <[email protected]>; Lasse Johnsen
> <[email protected]>; Vadim Fedorenko <[email protected]>; intel-
> [email protected]; [email protected]; linux-renesas-
> [email protected]
> Subject: Re: [PATCH net 1/5] igb: reject invalid external timestamp requests 
> for
> 82580-based HW
> 
> On Mon, Mar 10, 2025 at 03:16:36PM -0700, Jacob Keller wrote:
> > The igb_ptp_feature_enable_82580 function correctly checks that unknown
> > flags are not passed to the function. However, it does not actually check
> > PTP_RISING_EDGE or PTP_FALLING_EDGE when configuring the external
> timestamp
> > function.
> >
> > The data sheet for the 82580 product says:
> >
> >   Upon a change in the input level of one of the SDP pins that was
> >   configured to detect Time stamp events using the TSSDP register, a time
> >   stamp of the system time is captured into one of the two auxiliary time
> >   stamp registers (AUXSTMPL/H0 or AUXSTMPL/H1).
> >
> >   For example to define timestamping of events in the AUXSTMPL0 and
> >   AUXSTMPH0 registers, Software should:
> >
> >   1. Set the TSSDP.AUX0_SDP_SEL field to select the SDP pin that detects
> >      the level change and set the TSSDP.AUX0_TS_SDP_EN bit to 1.
> >
> >   2. Set the TSAUXC.EN_TS0 bit to 1 to enable timestamping
> >
> > The same paragraph is in the i350 and i354 data sheets.
> >
> > The wording implies that the time stamps are captured at any level change.
> > There does not appear to be any way to only timestamp one edge of the
> > signal.
> >
> > Reject requests which do not set both PTP_RISING_EDGE and
> PTP_FALLING_EDGE
> > when operating under PTP_STRICT_FLAGS mode via PTP_EXTTS_REQUEST2.
> >
> > Fixes: 38970eac41db ("igb: support EXTTS on 82580/i354/i350")
> > Signed-off-by: Jacob Keller <[email protected]>
> > ---
> >  drivers/net/ethernet/intel/igb/igb_ptp.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c
> b/drivers/net/ethernet/intel/igb/igb_ptp.c
> > index
> f9457055612004c10f74379122063e8136fe7d76..b89ef4538a18d7ca11325ddc1594
> 4a878f4d807e 100644
> > --- a/drivers/net/ethernet/intel/igb/igb_ptp.c
> > +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
> > @@ -509,6 +509,11 @@ static int igb_ptp_feature_enable_82580(struct
> ptp_clock_info *ptp,
> >                                     PTP_STRICT_FLAGS))
> >                     return -EOPNOTSUPP;
> >
> > +           /* Both the rising and falling edge are timstamped */
> > +           if (rq->extts.flags & PTP_STRICT_FLAGS &&
> > +               (rq->extts.flags & PTP_EXTTS_EDGES) != PTP_EXTTS_EDGES)
> > +                   return -EOPNOTSUPP;
> > +
> >             if (on) {
> >                     pin = ptp_find_pin(igb->ptp_clock, PTP_PF_EXTTS,
> >                                        rq->extts.index);
> 
> Thanks for fixing
> Reviewed-by: Michal Swiatkowski <[email protected]>
> 
> In igb_ptp_feature_enable_i210() there is the same check for both edges
> but also PTP_ENABLE_FEATURE is tested. There is no need for it here, or
> it is redundant even in i210?
> 

Hmm. It might be required, because requests to disable the clock won't have 
PTP_FEATURE_ENABLED set, and might have the edges cleared, which would prevent 
you from disabling the output..? I'll have to see what the kernel does when it 
disables the function.

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