From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: [PATCH 0/2] [RFC] posix clock tuning Date: Sat, 4 Sep 2010 20:47:39 -0500 (CDT) Message-ID: References: <4C828652.4060804@gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <4C828652.4060804-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christian Riesch Cc: Richard Cochran , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Sat, 4 Sep 2010, Christian Riesch wrote: > Richard's idea is to support clock hardware for IEEE 1588 (PTP, Precision Time > Protocol). Have a look at the earlier discussions: > > http://lkml.org/lkml/2010/8/16/90 A superficial scan does not give me any definite agreement on an approach. The patchset also needs to be CCed to John Stultz. Without a summary I still am not clear what this is supposed to address. Tuning of the PTP clock can be done with driver specific configuration rather than a new POSIX clock. That is at least how SGI_CYCLE is operating which is similar. > http://lkml.org/lkml/2010/8/23/49 Ok this goes more into something that may prove useful but it would be very helpful still to have a clear discussion as to why this is all needed. From what I can tell the functionality is already there and another clock device (CLOCK_SGI_CYCLE) is already providing a model for how a PTP clock could be controlled and used.