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From:   Min Li <min.li.xe@renesas.com>
To:     Richard Cochran <richardcochran@gmail.com>
CC:     "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH net 1/2] ptp: idt82p33: optimize idt82p33_adjtime
Thread-Topic: [PATCH net 1/2] ptp: idt82p33: optimize idt82p33_adjtime
Thread-Index: AQHXaD6QH3kS+d8DxUyFpooG2wAFo6sihNkAgAC1sPCAAB6rgIABcPxg
Date:   Fri, 25 Jun 2021 14:24:24 +0000
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Hi Richard

How would you suggest to implement the change that make the new driver beha=
vior optional?
There is no additional parameter in adjtime to let me do that.

Thanks

Min

> -----Original Message-----
> From: Richard Cochran <richardcochran@gmail.com>
> Sent: June 24, 2021 12:20 PM
> To: Min Li <min.li.xe@renesas.com>
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH net 1/2] ptp: idt82p33: optimize idt82p33_adjtime
>=20
> On Thu, Jun 24, 2021 at 02:38:46PM +0000, Min Li wrote:
> > I have tested this change with ptp4l for by setting step_window to 48
> > (assuming 16 packets per second) for both 8265.2/8275.1 and they
> performed well.
>=20
> Both of these patches assume that user space has a special configuration
> that works together with the non-standard driver behavior.
>=20
> For this reason, I suggest making the new driver behavior optional, with =
the
> default being the origin version that "just works".  In that way, the
> admin/user can choose the special configuration on purpose, and the
> default performance will not be degraded.
>=20
> Thanks,
> Richard