From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4222BC32750 for ; Tue, 13 Aug 2019 07:58:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21ED820679 for ; Tue, 13 Aug 2019 07:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728050AbfHMH6M (ORCPT ); Tue, 13 Aug 2019 03:58:12 -0400 Received: from mga02.intel.com ([134.134.136.20]:26608 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726986AbfHMH6M (ORCPT ); Tue, 13 Aug 2019 03:58:12 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Aug 2019 00:50:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,380,1559545200"; d="scan'208";a="375517226" Received: from pipin.fi.intel.com (HELO pipin) ([10.237.72.175]) by fmsmga005.fm.intel.com with ESMTP; 13 Aug 2019 00:50:07 -0700 From: Felipe Balbi To: Andrew Lunn Cc: Richard Cochran , netdev@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, "Christopher S . Hall" Subject: Re: [RFC PATCH 0/5] PTP: add support for Intel's TGPIO controller In-Reply-To: <20190719132021.GC24930@lunn.ch> References: <20190716072038.8408-1-felipe.balbi@linux.intel.com> <20190718195040.GL25635@lunn.ch> <87h87isci5.fsf@linux.intel.com> <20190719132021.GC24930@lunn.ch> Date: Tue, 13 Aug 2019 10:50:06 +0300 Message-ID: <87wofhy05t.fsf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, Andrew Lunn writes: >> Andrew Lunn writes: >> > On Tue, Jul 16, 2019 at 10:20:33AM +0300, Felipe Balbi wrote: >> >> TGPIO is a new IP which allows for time synchronization between systems >> >> without any other means of synchronization such as PTP or NTP. The >> >> driver is implemented as part of the PTP framework since its features >> >> covered most of what this controller can do. >> > >> > Hi Felipe >> > >> > Given the name TGPIO, can it also be used for plain old boring GPIO? >> >> not really, no. This is a misnomer, IMHO :-) We can only assert output >> pulses at specified intervals or capture a timestamp of an external >> signal. > > Hi Felipe > > So i guess Intel Marketing wants to call it a GPIO, but between > engineers can we give it a better name? If we do that we make it difficult for those reading specification and trying to find the matching driver. >> > Also, is this always embedded into a SoC? Or could it actually be in a >> > discrete NIC? >> >> Technically, this could be done as a discrete, but it isn't. In any >> case, why does that matter? From a linux-point of view, we have a device >> driver either way. > > I've seen a lot of i210 used with ARM SoCs. How necessary is the tsc > patch? Is there an architecture independent alternative? Without the TSC patch, we don't get the timestamp we need. One can argue that $this driver could call get_tsc_ns() directly instead of providing a wrapper for it. But that's something else entirely. -- balbi