Re: PPS functionality for Intel Timed I/O

[Rodolfo Giometti]

On 06/10/23 07:31, N, Pandith wrote:
> Hi,

Hello.

> > -----Original Message-----
> > From: Rodolfo Giometti <giometti@xxxxxxxxxxxx>
> > Sent: Wednesday, February 15, 2023 1:16 PM
> > To: N, Pandith <pandith.n@xxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; Sangannavar, Mallikarjunappa
> > <mallikarjunappa.sangannavar@xxxxxxxxx>; D, Lakshmi Sowjanya
> > <lakshmi.sowjanya.d@xxxxxxxxx>; T R, Thejesh Reddy
> > <thejesh.reddy.t.r@xxxxxxxxx>; Hall, Christopher S
> > <christopher.s.hall@xxxxxxxxx>; Gross, Mark <mark.gross@xxxxxxxxx>
> > Subject: Re: PPS functionality for Intel Timed I/O
> >
> > On 15/02/23 08:09, N, Pandith wrote:
> > > Hi Rodolfo,
> >
> > Hello.
> >
> > > > -----Original Message-----
> > > > From: Rodolfo Giometti <giometti@xxxxxxxxxxxx>
> > > > Sent: Monday, February 6, 2023 4:17 PM
> > > > To: N, Pandith <pandith.n@xxxxxxxxx>
> > > > Cc: linux-kernel@xxxxxxxxxxxxxxx; Sangannavar, Mallikarjunappa
> > > > <mallikarjunappa.sangannavar@xxxxxxxxx>; D, Lakshmi Sowjanya
> > > > <lakshmi.sowjanya.d@xxxxxxxxx>; T R, Thejesh Reddy
> > > > <thejesh.reddy.t.r@xxxxxxxxx>; Hall, Christopher S
> > > > <christopher.s.hall@xxxxxxxxx>
> > > > Subject: Re: PPS functionality for Intel Timed I/O
> >
> > [snip]
> >
> > > > Mmm... I'm not sure this is correct since PPS generators should
> > > > generate their pulses according to system clock and not according to
> > > > their internal clocks even if they are synced with the system clock.
> > > Timed I/O and system time are both driven by the *same* hardware clock.
> > > Timed I/O is a high precision device (nanoseconds), able to output pulses.
> > > The driver gets the system time and schedules output at target_time in
> > > the future.
> >
> > OK, in this case it would be OK. Please put an appropriate note within the
> > generator's code and a detailed one within Documentation/driver-api/pps.rst.
> >
> > Regarding Documentation/driver-api/pps.rst let me suggest you to prose a
> > separate patch to rewrite the Generators section in such a way you easily can add
> > your solution at the end. A possible example is attached but feel free to rewrite it
> > according to your needs.
> Ok, we are updating documentation as you have suggested as a separate patch.
> Can we use your "Signed-off-by" tag for attached patch.

If you just followed my suggestion then it's OK for me.

> We are adding Intel timed I/O documentation as a separate patch.

OK.

Ciao,

Rodolfo Giometti

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