From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757524AbbIDILe (ORCPT ); Fri, 4 Sep 2015 04:11:34 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:37452 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751939AbbIDIL2 (ORCPT ); Fri, 4 Sep 2015 04:11:28 -0400 Date: Fri, 4 Sep 2015 10:11:22 +0200 From: Richard Cochran To: "Hall, Christopher S" Cc: Thomas Gleixner , "Kirsher, Jeffrey T" , "hpa@zytor.com" , "mingo@redhat.com" , "john.stultz@linaro.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" , "intel-wired-lan@lists.osuosl.org" , "peterz@infradead.org" Subject: Re: [PATCH v3 1/4] Add correlated clocksource deriving system time from an auxiliary clocksource Message-ID: <20150904081122.GA4201@netboy> References: <1440183128-1384-1-git-send-email-christopher.s.hall@intel.com> <1440183128-1384-2-git-send-email-christopher.s.hall@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 03, 2015 at 11:20:37PM +0000, Hall, Christopher S wrote: > In addition to the network interface, ART will be used in the audio interface as well. > We need to support the case where an audio co-processor will control the audio device. > In this case, the get_ts() function supplied by the audio driver will be very slow > (several milliseconds) and the result will be out of date by some fraction of that > amount. Why does it take milliseconds to read one audio time stamp? Thanks, Richard