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=-3.8 required=3.0 tests=BAYES_00, 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 B39C8C433E0 for ; Sun, 24 Jan 2021 19:12:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F3B122D50 for ; Sun, 24 Jan 2021 19:12:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726334AbhAXTM0 (ORCPT ); Sun, 24 Jan 2021 14:12:26 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:57034 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726164AbhAXTMY (ORCPT ); Sun, 24 Jan 2021 14:12:24 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1l3knT-002Pg1-CC; Sun, 24 Jan 2021 20:11:39 +0100 Date: Sun, 24 Jan 2021 20:11:39 +0100 From: Andrew Lunn To: Stefan Chulski Cc: Russell King - ARM Linux admin , "netdev@vger.kernel.org" , "thomas.petazzoni@bootlin.com" , "davem@davemloft.net" , Nadav Haklai , Yan Markman , "linux-kernel@vger.kernel.org" , "kuba@kernel.org" , "mw@semihalf.com" , "atenart@kernel.org" Subject: Re: [EXT] Re: [PATCH v2 RFC net-next 08/18] net: mvpp2: add FCA periodic timer configurations Message-ID: References: <1611488647-12478-1-git-send-email-stefanc@marvell.com> <1611488647-12478-9-git-send-email-stefanc@marvell.com> <20210124121443.GU1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Jan 24, 2021 at 02:43:30PM +0000, Stefan Chulski wrote: > > > > ---------------------------------------------------------------------- > > On Sun, Jan 24, 2021 at 01:43:57PM +0200, stefanc@marvell.com wrote: > > > +/* Set Flow Control timer x140 faster than pause quanta to ensure > > > +that link > > > + * partner won't send taffic if port in XOFF mode. > > > > Can you explain more why 140 times faster is desirable here? Why 140 times > > and not, say, 10 times faster? Where does this figure come from, and what is > > the reasoning? Is there a switch that requires it? > > I tested with 140. > Actually regarding to spec each quanta should be equal to 512 bit times. > In 10G bit time is 0.1ns. And if the link has been negotiated to 10Mbps? Or is the clock already scaled to the link speed? Andrew