From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [PATCH net-next v2 1/8] net-timestamp: explicit SO_TIMESTAMPING ancillary data struct Date: Mon, 7 Jul 2014 22:18:17 +0200 Message-ID: <20140707201817.GA10683@localhost.localdomain> References: <1404416380-3545-1-git-send-email-willemb@google.com> <1404416380-3545-2-git-send-email-willemb@google.com> <20140705201851.GE3869@localhost.localdomain> <20140707184700.GA1610@localhost.localdomain> <53BAF8AC.6010907@cavium.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Willem de Bruijn , netdev@vger.kernel.org, David Miller , Eric Dumazet , Stephen Hemminger , Chad Reese , David Daney To: Chad Reese Return-path: Received: from mail-wi0-f169.google.com ([209.85.212.169]:62226 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750979AbaGGUSk (ORCPT ); Mon, 7 Jul 2014 16:18:40 -0400 Received: by mail-wi0-f169.google.com with SMTP id hi2so76021wib.0 for ; Mon, 07 Jul 2014 13:18:39 -0700 (PDT) Content-Disposition: inline In-Reply-To: <53BAF8AC.6010907@cavium.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jul 07, 2014 at 12:44:44PM -0700, Chad Reese wrote: > > For Octeon, you can optionally use the hardware timestamp as the > system clock reference. Most people don't, but it is the only way to > get the system time to be accurate. 1588 can synchronize two Octeon > boards to less than 1ns for the hardware timer. The Linux software > timers is always farther off. Did you mean 1us ? Thanks, Richard