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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E832EE4996 for ; Mon, 21 Aug 2023 05:32:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233176AbjHUFcc convert rfc822-to-8bit (ORCPT ); Mon, 21 Aug 2023 01:32:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233142AbjHUFcb (ORCPT ); Mon, 21 Aug 2023 01:32:31 -0400 Received: from rtits2.realtek.com.tw (rtits2.realtek.com [211.75.126.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C3DF0A3; Sun, 20 Aug 2023 22:32:27 -0700 (PDT) Authenticated-By: X-SpamFilter-By: ArmorX SpamTrap 5.77 with qID 37L5VLoK4004057, This message is accepted by code: ctloc85258 Received: from mail.realtek.com (rtexh36505.realtek.com.tw[172.21.6.25]) by rtits2.realtek.com.tw (8.15.2/2.81/5.90) with ESMTPS id 37L5VLoK4004057 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 21 Aug 2023 13:31:21 +0800 Received: from RTEXMBS06.realtek.com.tw (172.21.6.99) by RTEXH36505.realtek.com.tw (172.21.6.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.32; Mon, 21 Aug 2023 13:31:10 +0800 Received: from RTEXMBS04.realtek.com.tw (172.21.6.97) by RTEXMBS06.realtek.com.tw (172.21.6.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 21 Aug 2023 13:31:10 +0800 Received: from RTEXMBS04.realtek.com.tw ([fe80::e138:e7f1:4709:ff4d]) by RTEXMBS04.realtek.com.tw ([fe80::e138:e7f1:4709:ff4d%5]) with mapi id 15.01.2375.007; Mon, 21 Aug 2023 13:31:10 +0800 From: Justin Lai To: Andrew Lunn CC: "kuba@kernel.org" , "davem@davemloft.net" , "edumazet@google.com" , "pabeni@redhat.com" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" Subject: RE: [PATCH net-next v3 1/2] net/ethernet/realtek: Add Realtek automotive PCIe driver code Thread-Topic: [PATCH net-next v3 1/2] net/ethernet/realtek: Add Realtek automotive PCIe driver code Thread-Index: AQHZz4Ya38d07ViN20S7bf3O9T4Qta/q9pcAgAMgk2D//87KAIABzfpQ///CfgCABJnu0A== Date: Mon, 21 Aug 2023 05:31:09 +0000 Message-ID: <6d35d56f78b7452b9330c3257748fa3c@realtek.com> References: <20230815143756.106623-1-justinlai0215@realtek.com> <20230815143756.106623-2-justinlai0215@realtek.com> <95f079a4-19f9-4501-90d9-0bcd476ce68d@lunn.ch> <4955506dbf6b4ebdb67cbb738750fbc8@realtek.com> <4951391892534eaeb2da96f052364e4c@realtek.com> <4b630aeb-3098-4108-b8dc-7da6e55a7cf1@lunn.ch> In-Reply-To: <4b630aeb-3098-4108-b8dc-7da6e55a7cf1@lunn.ch> Accept-Language: zh-TW, en-US Content-Language: zh-TW X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.21.210.185] x-kse-serverinfo: RTEXMBS06.realtek.com.tw, 9 x-kse-antispam-interceptor-info: fallback x-kse-antivirus-interceptor-info: fallback Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-KSE-AntiSpam-Interceptor-Info: fallback X-KSE-ServerInfo: RTEXH36505.realtek.com.tw, 9 X-KSE-AntiSpam-Interceptor-Info: fallback X-KSE-Antivirus-Interceptor-Info: fallback X-KSE-AntiSpam-Interceptor-Info: fallback Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > > Is the 'line' speed of the MAC fixed? It operates at one speed, and that is > it? > > > > Hi, Andrew > > > > > The "line" speed of the MAC is fixed 5G, but the throughput will be > > determined according to the speed of the PCIe link. For example, if > > the link speed is gen 3, the throughput will be 5G. if the link speed > > is gen 2, the throughput will be 2.5G. if the link speed is gen 1, the > > throughput will be 1G. > > ksettings does not return throughput, it returns the line speed. throughput is > determined by a lot of different things, can the CPU handle frames fast enough, > is the memory bandwidth high enough, what is happening on other ports of > the PCIe switch etc. > > There is at least one driver i know of which reports a warning at probe time, if > it finds the device is on a bus which cannot support the full bandwidth. Maybe > copy that. > Hi, Andrew Thanks for your guidance, we have represented the actual connection speed in the next version. > > There is no extra fields in DMA descriptors for tagging protocol. The > > tag added by switch hardware instead of this driver. > > > > Are the I2C, MDIO and SPI bus masters also hanging off a PCIE > > > endpoint? Can they probe independently? I'm just want to check this > > > should not be part of an MFD driver. > > > > > The I2C, MDIO and SPI bus masters are not hanging off the PCIE > > endpoints, but on the switch core. > > So the switch core is also an PCIE endpoint? Sorry, please allow me to explain again. The RTL90xx Series supports I2C, MDC/MDIO and SPI slave to access the registers of Ethernet Switch Core and the external CPU could manage it via these pins. You are right, there is a tag protocol in the switch core. But It's for the other ports, usually the cpu port, not this pcie gmac interface. You can think of this pcie gmac as a NIC connecting to the external ethernet switch directly. > > Andrew > .