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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 985FAC63798 for ; Tue, 17 Nov 2020 15:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 561992466D for ; Tue, 17 Nov 2020 15:11:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pMmlPRXq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730440AbgKQPLY (ORCPT ); Tue, 17 Nov 2020 10:11:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:58658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730209AbgKQPLX (ORCPT ); Tue, 17 Nov 2020 10:11:23 -0500 Received: from mail-ot1-f48.google.com (mail-ot1-f48.google.com [209.85.210.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B1DFA2466D; Tue, 17 Nov 2020 15:11:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605625882; bh=C4yS4FgGZ20hDfC8vb6+iWWOh9UGXCtT+oSCVv0lIc4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=pMmlPRXqfc4CNOJBE61Lq46N8AufvzV0juXIToPXF9eSdyh+5jf+xJwAuxBifBWRn 6xKCPPS9lE6kx/zKjAtyEzngPlkHYG0JMLJEq4ZfJ1VDicVVXbhkveW3gzSbRKzNf0 wO5JS4ODDm/If1lwxEtd6+2d4bHy7AmDOsh/yK9s= Received: by mail-ot1-f48.google.com with SMTP id j14so19727971ots.1; Tue, 17 Nov 2020 07:11:22 -0800 (PST) X-Gm-Message-State: AOAM5326iwHhqA8Lc02HqF3qRljUSkBAWL3tN4Q99hfmMWygNxA+FWty ZCCRvwWJmPOGkXlhi20xU6I2cMszPEnUuANPvwg= X-Google-Smtp-Source: ABdhPJzPDDDU77Y0ooUlA2nKsjWglmGXsBwnC46xjWewyrbSPbTP1FKa46jAA1eQXgiQ5xjfh5Pjb9fXC8wikOToY/s= X-Received: by 2002:a05:6830:22d2:: with SMTP id q18mr3025922otc.305.1605625881933; Tue, 17 Nov 2020 07:11:21 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Tue, 17 Nov 2020 16:11:06 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 0/5] misc: Add Add Synopsys DesignWare xData IP driver To: Gustavo Pimentel Cc: Joao Pinto , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Jonathan Corbet , linux-pci , "open list:DOCUMENTATION" , "linux-kernel@vger.kernel.org" , Kishon Vijay Abraham I , Lorenzo Pieralisi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 17, 2020 at 3:53 PM Gustavo Pimentel wrote: > On Tue, Nov 17, 2020 at 14:4:49, Arnd Bergmann wrote: > > On Fri, Nov 13, 2020 at 11:37 PM Gustavo Pimentel wrote: > > > > > > This patch series adds a new driver called xData-pcie for the Synopsys > > > DesignWare PCIe prototype. > > > > > > The driver configures and enables the Synopsys DesignWare PCIe traffic > > > generator IP inside of prototype Endpoint which will generate upstream > > > and downstream PCIe traffic. This allows to quickly test the PCIe link > > > throughput speed and check is the prototype solution has some limitation > > > or not. > > > > I don't quite understand what this hardware is, based on your description. > > Is this a specific piece of hardware that only serves as a traffic generator, > > or a particular hardware feature of the DesignWare endpoint, or is it > > software running on a SoC in endpoint mode while plugged into a Linux > > system running this driver on the host? > > Firstly you have to have in mind that we are talking about an HW > prototype based on FPGA. This PCIe Endpoint HW prototype from Synopsys > might have multiple HW blocks inside (depends on the HW design), in this > particular prototype case, it has an HW block is called xData (available > internally to Synopsys only) which is a PCIe traffic generator, this > block has no practical usage, unless for HW validation and testing new > designs that push forward new PCIe speeds. Ok, got it. Thanks for the explanation. > > My feeling is that this should be located more closely to drivers/pci/, > > but that depends on what it actually does. > > I thought to put on /misc because the purpose is very limited and doesn't > fit in a normal case. Makes sense. I usually try to ensure we don't add anything to drivers/misc that could reasonably be grouped with related code elsewhere, but I agree there isn't much that fits into this category today, so let's leave it there unless someone comes up with a better idea. The only alternative I could see would be drivers/pci/testing/ Arnd