From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [net-next PATCH 29/29] fm10k: Add support for PTP Date: Sat, 20 Sep 2014 23:16:49 +0200 Message-ID: <20140920211647.GB5258@netboy> References: <20140918223242.10373.27403.stgit@ahduyck-bv4.jf.intel.com> <20140918224042.10373.93162.stgit@ahduyck-bv4.jf.intel.com> <20140919173504.GA4136@localhost.localdomain> <541C76B8.6040708@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, nhorman@redhat.com, netdev@vger.kernel.org, john.fastabend@gmail.com, matthew.vick@intel.com, jeffrey.t.kirsher@intel.com, sassmann@redhat.com To: Alexander Duyck Return-path: Received: from mail-we0-f175.google.com ([74.125.82.175]:55426 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754627AbaITVQy (ORCPT ); Sat, 20 Sep 2014 17:16:54 -0400 Received: by mail-we0-f175.google.com with SMTP id u57so386302wes.34 for ; Sat, 20 Sep 2014 14:16:53 -0700 (PDT) Content-Disposition: inline In-Reply-To: <541C76B8.6040708@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Sep 19, 2014 at 11:32:24AM -0700, Alexander Duyck wrote: > > Because the value cannot be adjusted directly. The timesource for the > switch is shared by all ports and host interfaces. As such we have to > maintain a software offset per host to avoid corrupting the other clocks. So any host can set the time, but only one may adjust the frequency? Regarding the overflow, probably you can remove the daily check, since you only need a single clock read every 300 years, and that is reasonable to expect in any case. Thanks, Richard