netdev - Re: [PATCH net-next v2 2/2] qede: Add driver support for PTP.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170131145318.GA18274@localhost.localdomain>
Date:   Tue, 31 Jan 2017 15:53:18 +0100
From:   Richard Cochran <richardcochran@...il.com>
To:     "Mintz, Yuval" <Yuval.Mintz@...ium.com>
Cc:     David Laight <David.Laight@...LAB.COM>,
        "Kalluru, Sudarsana" <Sudarsana.Kalluru@...ium.com>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next v2 2/2] qede: Add driver support for PTP.

On Tue, Jan 31, 2017 at 02:31:41PM +0000, Mintz, Yuval wrote:
> I feel like I'm missing something. Again.
> I thought the reasonable rate of rate-adjustment is once a second,
> which doesn't make it 'hot' in any way.
> In which scenario would we frequently encounter this configuration?

The Sync message rate is not 1 per second, but rather the interval is
specified by the PTP profile as 2^N seconds, -128 <= N < 128.

This is called the logSyncInterval, and in the Telecom profile [1] for
example, N = -4.

Anyhow, as far the original question goes, maybe you could have the
specific HW driver pass its adjfreq function pointer into the generic
driver and let the generic driver copy it directly into the
ptp_clock_info.

Just an idea.

Thanks,
Richard

1. T-REC-G.8275.1-201407