Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754637AbcKUNtB (ORCPT ); Mon, 21 Nov 2016 08:49:01 -0500 Received: from smtprelay2.synopsys.com ([198.182.60.111]:54147 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753975AbcKUNs7 (ORCPT ); Mon, 21 Nov 2016 08:48:59 -0500 Subject: Re: Synopsys Ethernet QoS Driver To: Giuseppe CAVALLARO , Joao Pinto , Rayagond Kokatanur , Rabin Vincent References: <1dbb6047-2bbb-4d56-2a62-ab65a0254844@synopsys.com> <20161119135654.GA14079@lnxartpec.se.axis.com> <1248f4ce-4859-10e6-fef9-342ea543f8d4@synopsys.com> <87c8a24b-0812-7850-cb3f-7be691bab432@st.com> CC: mued dib , David Miller , "Jeff Kirsher" , , , , netdev , , , , , , "linux-arm-kernel@lists.infradead.org" From: Joao Pinto Message-ID: Date: Mon, 21 Nov 2016 13:48:53 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <87c8a24b-0812-7850-cb3f-7be691bab432@st.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.107.25.130] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3812 Lines: 101 Hello Peppe, On 21-11-2016 12:52, Giuseppe CAVALLARO wrote: > Hello Joao > > On 11/21/2016 1:32 PM, Joao Pinto wrote: >> Hello, >> >> On 21-11-2016 05:29, Rayagond Kokatanur wrote: >>> On Sat, Nov 19, 2016 at 7:26 PM, Rabin Vincent wrote: >>>> On Fri, Nov 18, 2016 at 02:20:27PM +0000, Joao Pinto wrote: >>>>> For now we are interesting in improving the synopsys QoS driver under >>>>> /nect/ethernet/synopsys. For now the driver structure consists of a single >>>>> file >>>>> called dwc_eth_qos.c, containing synopsys ethernet qos common ops and platform >>>>> related stuff. >>>>> >>>>> Our strategy would be: >>>>> >>>>> a) Implement a platform glue driver (dwc_eth_qos_pltfm.c) >>>>> b) Implement a pci glue driver (dwc_eth_qos_pci.c) >>>>> c) Implement a "core driver" (dwc_eth_qos.c) that would only have Ethernet QoS >>>>> related stuff to be reused by the platform / pci drivers >>>>> d) Add a set of features to the "core driver" that we have available >>>>> internally >>>> >>>> Note that there are actually two drivers in mainline for this hardware: >>>> >>>> drivers/net/ethernet/synopsis/ >>>> drivers/net/ethernet/stmicro/stmmac/ >>> >>> Yes the later driver (drivers/net/ethernet/stmicro/stmmac/) supports >>> both 3.x and 4.x. It has glue layer for pci, platform, core etc, >>> please refer this driver once before you start. >>> >>> You can start adding missing feature of 4.x in stmmac driver. >> >> Thanks you all for all the info. >> Well, I think we are in a good position to organize the ethernet drivers >> concerning Synopsys IPs. >> >> First of all, in my opinion, it does not make sense to have a ethernet/synopsis >> (typo :)) when ethernet/stmicro is also for a synopsys IP. If we have another >> vendor using the same IP it should be able to reuse the commonn operations. But >> I would put that discussion for later :) >> >> For now I suggest that for we create ethernet/qos and create there a folder >> called dwc (designware controller) where all the synopsys qos IP specific code >> in order to be reused for example by ethernet/stmicro/stmmac/. We just have to >> figure out a clean interface for "client drivers" like stmmac to interact with >> the new qos driver. >> >> What do you think about this approach? > > The stmmac drivers run since many years on several platforms > (sh4, stm32, arm, x86, mips ...) and it supports an huge of amount of > configurations starting from 3.1x to 3.7x databooks. Great! > > It also supports QoS hardware; for example, 4.00a, 4.10a and 4.20a > are fully working. Synopsys QoS IP is a separated hardware component, so it should be reusable by all implementations using it and so have its own "core driver" and platform + pci glue drivers. This is necessary for example in hardware validation, where you prototype an IP and instantiate its drivers and test it. Was there a strong reason to integrate QoS features directly in stmmac and not in synopsys/dwc_eth_qos.*? > > Also the stmmac has platform, device-tree and pcie supports and > a lot of maintained glue-logic files. > > It is fully documented inside the kernel tree. Thanks for the information, I am going to check it out. > > I am happy to have new enhancements from other developers. > So, on my side, if you want to spend your time on improving it on your > platforms please feel free to do it! > > Concerning the stmicro/stmmac naming, these come from a really old > story and have no issue to adopt new folder/file names. Thank you for your availability! > > I am also open to merge fixes and changes from ethernet/synopsis. > I want to point you on some benchmarks made by Alex some months ago > (IIRC) that showed an stmmac winner (due to the several optimizations > analyzed and reviewed in this mailing list). > > Peppe > Thanks Joao