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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1623EC0650F for ; Tue, 30 Jul 2019 16:20:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDE4E206E0 for ; Tue, 30 Jul 2019 16:20:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bztm95dB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731076AbfG3QUO (ORCPT ); Tue, 30 Jul 2019 12:20:14 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:37434 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbfG3QUO (ORCPT ); Tue, 30 Jul 2019 12:20:14 -0400 Received: by mail-lj1-f193.google.com with SMTP id z28so8423828ljn.4; Tue, 30 Jul 2019 09:20:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LZrs3EXzgagsIRWCcK5WoYuGudeHWQiiXYHAwY61jDU=; b=bztm95dBwDr9C9kSDpfKQcPwa2EypHieXjU6mFF73TIPVFDKcC+ZVsfd5MIFcmOQni 6AGtZxd9HPhpqBM05juVJGHPE+hVWeUJ1Fnw49h+YBITPeGKyVElOd1zUXW3qVgyAN/y J+6kp9BfjQLTC+h276H7ZKL+dzzVushEH6yau7rU7nx20Z/q/MReNPKpPXOiCmQrTRyF H4aQv/uOK1PETLR0Pfh5NvjdgMg1sqn2VBpFv2MzYDz8twUFNWifgNC16VqBdIF5pVdt hXk24tfKJ7yW7tu3zEgVBVShz0r5w0VZ5PC/ALRl1Gq0qUJ33SUFW/fgyanzEAAPqJQP qL5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LZrs3EXzgagsIRWCcK5WoYuGudeHWQiiXYHAwY61jDU=; b=ijd0ln9JDqrA26OhREnviCZEjvANFOHs0cc6DI6ZvG5jB9uyVWzJKYJFgeTSv+/4jU F7ftDzZ7zkvXXRPRVUfvuaVFhIALu6zkj46eYKj6A7CYAsZPcBflZrOanwvE6idQnQR/ aoVTLPVXjPe8cLNUJc8tWCg/ZJM/PxLvUqgMm39/Tv7JrHlKS5Zr0QZpAHARmsS/AD2t XwzCfYPDUK4cgjXA85jAdnyKJSFw/ILO0S0aPoWvoLS/e9Ag5cPW1Z3vgf4heqHBfnTu 2kPRLnDmPuOjY/ZT0XOmN387f0XqgX+uLmBBG6aYfLrCtDDZoQM5XtNVrorvqSgAKnY3 i1Zg== X-Gm-Message-State: APjAAAW18YFQjSbKkDeVsqLQKzaaDFzA1A2GQXtyQSIkgbjCG5BoaDHU 0ZKcd4nU35XQ8IzXJ22Hu35Exe76b32EDJIEYuo= X-Google-Smtp-Source: APXvYqzTQaxZoBfOrS9yI46mqu2ma/TkyeR74iuHX1SlyTMwjGIa7kAWW2W4RvuHsFshA3b4kO+EgrJJZ6pEcRP1A5E= X-Received: by 2002:a2e:870f:: with SMTP id m15mr61727485lji.223.1564503612218; Tue, 30 Jul 2019 09:20:12 -0700 (PDT) MIME-Version: 1.0 References: <20190730100429.32479-1-h.feurstein@gmail.com> <20190730100429.32479-5-h.feurstein@gmail.com> <20190730160032.GA1251@localhost> In-Reply-To: <20190730160032.GA1251@localhost> From: Hubert Feurstein Date: Tue, 30 Jul 2019 18:20:00 +0200 Message-ID: Subject: Re: [PATCH 4/4] net: dsa: mv88e6xxx: add PTP support for MV88E6250 family To: Richard Cochran Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Lunn , Vivien Didelot , Florian Fainelli , "David S. Miller" , Rasmus Villemoes Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Richard, thank you for your comments. Am Di., 30. Juli 2019 um 18:00 Uhr schrieb Richard Cochran : [...] > > -/* Raw timestamps are in units of 8-ns clock periods. */ > > -#define CC_SHIFT 28 > > -#define CC_MULT (8 << CC_SHIFT) > > -#define CC_MULT_NUM (1 << 9) > > -#define CC_MULT_DEM 15625ULL > > +/* The adjfine API clamps ppb between [-32,768,000, 32,768,000], and > > That is not true. > > > + * therefore scaled_ppm between [-2,147,483,648, 2,147,483,647]. > > + * Set the maximum supported ppb to a round value smaller than the maximum. > > + * > > + * Percentually speaking, this is a +/- 0.032x adjustment of the > > + * free-running counter (0.968x to 1.032x). > > + */ > > +#define MV88E6XXX_MAX_ADJ_PPB 32000000 > > I had set an arbitrary limit of 1000 ppm. I can't really see any > point in raising the limit. > > > +/* Family MV88E6250: > > + * Raw timestamps are in units of 10-ns clock periods. > > + * > > + * clkadj = scaled_ppm * 10*2^28 / (10^6 * 2^16) > > + * simplifies to > > + * clkadj = scaled_ppm * 2^7 / 5^5 > > + */ > > +#define MV88E6250_CC_SHIFT 28 > > +#define MV88E6250_CC_MULT (10 << MV88E6250_CC_SHIFT) > > +#define MV88E6250_CC_MULT_NUM (1 << 7) > > +#define MV88E6250_CC_MULT_DEM 3125ULL > > + > > +/* Other families: > > + * Raw timestamps are in units of 8-ns clock periods. > > + * > > + * clkadj = scaled_ppm * 8*2^28 / (10^6 * 2^16) > > + * simplifies to > > + * clkadj = scaled_ppm * 2^9 / 5^6 > > + */ > > +#define MV88E6XXX_CC_SHIFT 28 > > +#define MV88E6XXX_CC_MULT (8 << MV88E6XXX_CC_SHIFT) > > +#define MV88E6XXX_CC_MULT_NUM (1 << 9) > > +#define MV88E6XXX_CC_MULT_DEM 15625ULL > > > > #define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100) > > > > @@ -179,24 +206,14 @@ static void mv88e6352_tai_event_work(struct work_struct *ugly) > > static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) > > { > > struct mv88e6xxx_chip *chip = ptp_to_chip(ptp); > > - int neg_adj = 0; > > - u32 diff, mult; > > - u64 adj; > > + s64 adj; > > > > - if (scaled_ppm < 0) { > > - neg_adj = 1; > > - scaled_ppm = -scaled_ppm; > > - } > > Please don't re-write this logic. It is written like that for a reason. I used the sja1105_ptp.c as a reference. So it is also wrong there. Hubert