Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754735AbcKUPGo (ORCPT ); Mon, 21 Nov 2016 10:06:44 -0500 Received: from smtprelay2.synopsys.com ([198.182.60.111]:55332 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754527AbcKUPGk (ORCPT ); Mon, 21 Nov 2016 10:06:40 -0500 Subject: Re: Synopsys Ethernet QoS Driver To: Giuseppe CAVALLARO , Lars Persson 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: Joao Pinto , Rayagond Kokatanur , Rabin Vincent , mued dib , David Miller , Jeff Kirsher , "jiri@mellanox.com" , "saeedm@mellanox.com" , "idosch@mellanox.com" , netdev , "linux-kernel@vger.kernel.org" , "CARLOS.PALMINHA@synopsys.com" , =?UTF-8?Q?Andreas_Irest=c3=a5l?= , "alexandre.torgue@st.com" , "linux-arm-kernel@lists.infradead.org" From: Joao Pinto Message-ID: Date: Mon, 21 Nov 2016 15:06:23 +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: Content-Type: text/plain; charset="windows-1252" 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: 4943 Lines: 140 On 21-11-2016 14:25, Giuseppe CAVALLARO wrote: > On 11/21/2016 2:28 PM, Lars Persson wrote: >> >> >>> 21 nov. 2016 kl. 13:53 skrev Giuseppe CAVALLARO : >>> >>> 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. >>> >>> It also supports QoS hardware; for example, 4.00a, 4.10a and 4.20a >>> are fully working. >>> >>> 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. >>> >>> 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. >>> >>> 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 >>> >> >> Hello Joao and others, >> Hi Lars, >> As the maintainer of dwc_eth_qos.c I prefer also that we put efforts on the >> most mature driver, the stmmac. >> >> I hope that the code can migrate into an ethernet/synopsys folder to keep the >> convention of naming the folder after the vendor. This makes it easy for >> others to find the driver. >> >> The dwc_eth_qos.c will eventually be removed and its DT binding interface can >> then be implemented in the stmmac driver. So your ideia is to pick the ethernet/stmmac and rename it to ethernet/synopsys and try to improve the structure and add the missing QoS features to it? > > Thanks Lars, I will be happy to support all you on this transition > and I agree on renaming all. > > peppe > > >> - Lars >> >>>> >>>> >>>>> >>>>>> >>>>>> (See http://lists.openwall.net/netdev/2016/02/29/127) >>>>>> >>>>>> The former only supports 4.x of the hardware. >>>>>> >>>>>> The later supports 4.x and 3.x and already has a platform glue driver >>>>>> with support for several platforms, a PCI glue driver, and a core driver >>>>>> with several features not present in the former (for example: TX/RX >>>>>> interrupt coalescing, EEE, PTP). >>>>>> >>>>>> Have you evaluated both drivers? Why have you decided to work on the >>>>>> former rather than the latter? >>>>> >>>>> >>>> >>>> Thanks. >>>> >>>> >>>> >>>> >>> >> >