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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1B4D3C433E0 for ; Thu, 28 Jan 2021 16:48:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDDCC64E11 for ; Thu, 28 Jan 2021 16:48:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232658AbhA1QsR (ORCPT ); Thu, 28 Jan 2021 11:48:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232642AbhA1QoC (ORCPT ); Thu, 28 Jan 2021 11:44:02 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D3C3C061756; Thu, 28 Jan 2021 08:43:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=jr4vFfg++SnMXfOeSfc+6KemdjdKPH7hTDK3XX4rC9M=; b=KM3uQh4JFyuNplHnKH/rJXVnx J+cgzF8Z/PYEp3QUsF6JKWFkp4CZ/Vy71vvMoEjJbZheADzt5Bk1F8DvHVHK38s2DQR2VStlyAngC INbcXo9MYDcrLq8F49R8MN7rXdoeRQe0mxPYai0vQVO21rjwrnaj5Ea3YQVpN58B2yz019BxczEeU qEJS+ev1Qd2KDPMtL2qgVj1Wvq6lvar7kuzib0bmuyPnouM5tH/ZUIpY/iXjQKpf8MGj0EcxcQBZb fXIVOxtR8jN4hvymof8CDHVlLgkyYFA17y+Wb2pgQHZXaX3gkNVXdrcdNXx/FM6pw549uIKez+2Jj u4QJsk4dw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:53860) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l5AO6-0006sN-Nf; Thu, 28 Jan 2021 16:43:18 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1l5AO6-0005ye-02; Thu, 28 Jan 2021 16:43:18 +0000 Date: Thu, 28 Jan 2021 16:43:17 +0000 From: Russell King - ARM Linux admin To: stefanc@marvell.com Cc: netdev@vger.kernel.org, thomas.petazzoni@bootlin.com, davem@davemloft.net, nadavh@marvell.com, ymarkman@marvell.com, linux-kernel@vger.kernel.org, kuba@kernel.org, mw@semihalf.com, andrew@lunn.ch, atenart@kernel.org Subject: Re: [PATCH v4 net-next 00/19] net: mvpp2: Add TX Flow Control support Message-ID: <20210128164317.GS1551@shell.armlinux.org.uk> References: <1611747815-1934-1-git-send-email-stefanc@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1611747815-1934-1-git-send-email-stefanc@marvell.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King - ARM Linux admin Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 27, 2021 at 01:43:16PM +0200, stefanc@marvell.com wrote: > Armada hardware has a pause generation mechanism in GOP (MAC). > The GOP generate flow control frames based on an indication programmed in Ports Control 0 Register. There is a bit per port. > However assertion of the PortX Pause bits in the ports control 0 register only sends a one time pause. > To complement the function the GOP has a mechanism to periodically send pause control messages based on periodic counters. > This mechanism ensures that the pause is effective as long as the Appropriate PortX Pause is asserted. I've tested this on my Macchiatobin SingleShot, which seems to be Ax silicon (and I've checked a couple of my other Armada 8040 platforms which are also Ax silicon too) and networking remains functional without flow control with the gigabit port achieving wire speed. I have not yet tested the 10G ports. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!