From: Richard Cochran <richardcochran@gmail•com>
To: Christian Riesch <christian.riesch@omicron•at>
Cc: "Stefan Sørensen" <stefan.sorensen@spectralink•com>,
"David Miller" <davem@davemloft•net>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>
Subject: Re: [PATCH net-next 1/3] ptp: Allow reassigning calibration pin function
Date: Thu, 26 Jun 2014 16:57:20 +0200 [thread overview]
Message-ID: <20140626145720.GB10999@netboy> (raw)
In-Reply-To: <CABkLOboZDJr8tr5JpaUijuNcJ7j7L8nMU33TC0WMn4iir-qVAw@mail.gmail.com>
On Thu, Jun 26, 2014 at 08:14:58AM +0200, Christian Riesch wrote:
> On Thu, Jun 26, 2014 at 7:21 AM, Richard Cochran <richardcochran@gmail•com> wrote:
> > Reassigning the calibration function never makes sense, because it is
> > only used in the driver probe method.
>
> Yes, indeed, but isn't that a bug? I think the calibration should be
> done again whenever the clock is loaded with a new value, i.e. in
> ptp_dp83640_settime. See section 3.1 in [1]: "All subsequent settings
> should use a step
> adjustment or temporary rate adjustment, which should occur at each
> PHY without introducing any error." This means, whenever we do
> something else (directly write to the clock register), we must
> recalibrate.
When we write the time, we use the broadcast address, and so the PHYs
receive the data at exactly the same time on the MDIO bus. But maybe
they would still need a new, fine calibration. Can you test this?
(I don't have a board with two phys.)
Thanks,
Richard
next prev parent reply other threads:[~2014-06-26 14:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-25 12:37 [PATCH net-next 0/3] dp83640: Increase support perout pins Stefan Sørensen
2014-06-25 12:37 ` [PATCH net-next 1/3] ptp: Allow reassigning calibration pin function Stefan Sørensen
2014-06-26 5:21 ` Richard Cochran
2014-06-26 6:14 ` Christian Riesch
2014-06-26 6:16 ` Christian Riesch
2014-06-26 14:57 ` Richard Cochran [this message]
2014-06-25 12:37 ` [PATCH net-next 2/3] dp83640: Program pulsewidth2 values of perout triggers 0 and 1 Stefan Sørensen
2014-06-25 17:50 ` Sergei Shtylyov
2014-06-25 12:37 ` [PATCH net-next 3/3] dp83640: Increase supported perout pins to 7 Stefan Sørensen
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