From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: [PATCH V2 net-next 0/1] ptp: add pseudo pps ioctl Date: Wed, 31 Oct 2012 17:19:06 +0100 Message-ID: Cc: David Miller , Jacob Keller , John Stultz , Miroslav Lichvar To: Return-path: Received: from mail-ea0-f174.google.com ([209.85.215.174]:56974 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423233Ab2JaQTT (ORCPT ); Wed, 31 Oct 2012 12:19:19 -0400 Received: by mail-ea0-f174.google.com with SMTP id c13so623044eaa.19 for ; Wed, 31 Oct 2012 09:19:18 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: No changes in V2, except removing the RFC label and adding Jacob's ack. This patch adds a kind of "poor man's PPS" for use with those PHC drivers which do not support a true PPS. Using this ioctl, user space can estimate the system-phc offset and tune one of the clocks as desired. This patch has been tested on both the Intel igb (PCIe card) and the National Semiconductor phyter (PHY via MDIO bus), and the results seem quite promising. This patch avoids the "timecompare" code on purpose, since experiments have shown that code to be quite brittle, having been tuned to only one specific kind of hardware. Thanks, Richard Richard Cochran (1): ptp: add an ioctl to compare PHC time with system time drivers/ptp/ptp_chardev.c | 32 ++++++++++++++++++++++++++++++++ include/uapi/linux/ptp_clock.h | 14 ++++++++++++++ 2 files changed, 46 insertions(+), 0 deletions(-) -- 1.7.2.5