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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D0F59C4346E for ; Tue, 29 Sep 2020 04:19:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84F2420BED for ; Tue, 29 Sep 2020 04:19:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601353143; bh=BMF3qovafDLhF5xljF9JLinTdT9cAYHk8V34iiq5eTg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=km5O25vzRN0cqK6SmNalt1xesfLka+df4C+xiki1oPFOrfSpMLUH9L2OeibkTPqga H8f4m/KfYrOyu3i1Zw3ztE2OLSMreYeYTC1McpZiOmrYhOQXT4mitmmkRMVMrr9y07 TeEK+5PciLVDU3rPumZUQENsi/JJTvK9Bzlz/a/4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725554AbgI2ETD (ORCPT ); Tue, 29 Sep 2020 00:19:03 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:44479 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725497AbgI2ETD (ORCPT ); Tue, 29 Sep 2020 00:19:03 -0400 Received: by mail-pg1-f194.google.com with SMTP id 7so2787442pgm.11; Mon, 28 Sep 2020 21:19:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=W7ag7oUXRSKksDP87vpib6qEPD6wGpltDaRbB1u7nRw=; b=L/Z8iPnGaZbNz2v981/I5kCqEYX6bDMvXfwYEq0PrN8xwyLM0KJuZCxmTSV+gWgPwN tulqKCnUIqa0QJ0VubaUEntScgWei6PZ4icJ86ngz711HCQHSx4tfMoazc9OrQR7I57g AOO/LlDDYUWgWApW5D0tKCvoIDAXa3uasU1TMkjKD2pYxFjLYwbtVfUVaOycY4WlG2Mg 3BhmOXiPEOOfMu5U8DEokTX60PMKpJ3cbjwX6nahpSxHFp2wKCBqBX4UMO7bfWIxAbbP AJqDrcO4aDeq1iVIB5Qmtc0NfwviSkApEgRJwNmwhGVVbP6oKvEQHkZkGEGaOCcJFoRC GOWA== X-Gm-Message-State: AOAM531zNqsU+GgCI1Xhw5VLl+jdi6vFeNQvpAZPutuhlAjKXpV7vTvr iQo1fS1BloG0dRnN78OAxm4= X-Google-Smtp-Source: ABdhPJxtWaXRgIpcWHQr7lPr8/JuGTkV2huyCQwb8tVIYqhH3GUnCrlr3uwqf6I4JyLYP9wfHPlcOA== X-Received: by 2002:a62:1542:0:b029:150:e3f5:d8fc with SMTP id 63-20020a6215420000b0290150e3f5d8fcmr2331118pfv.66.1601353141715; Mon, 28 Sep 2020 21:19:01 -0700 (PDT) Received: from localhost ([2601:647:5b00:1162:1ac0:17a6:4cc6:d1ef]) by smtp.gmail.com with ESMTPSA id v21sm2890334pjn.4.2020.09.28.21.19.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Sep 2020 21:19:01 -0700 (PDT) Date: Mon, 28 Sep 2020 21:19:00 -0700 From: Moritz Fischer To: Xu Yilun Cc: mdf@kernel.org, Greg KH , linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, trix@redhat.com, lgoncalv@redhat.com, hao.wu@intel.com Subject: Re: [PATCH v3 1/5] fpga: dfl: rename the bus type "dfl" to "fpga-dfl" Message-ID: <20200929041900.GA113620@archbook> References: <1600966801-30586-2-git-send-email-yilun.xu@intel.com> <20200924172700.GA79736@archbook> <20200926022346.GA5623@yilunxu-OptiPlex-7050> <20200926060913.GA637197@kroah.com> <20200926192219.GA18625@epycbox.lan> <20200927055108.GA701198@kroah.com> <20200927073754.GB16433@yilunxu-OptiPlex-7050> <20200927075401.GA748141@kroah.com> <20200927083647.GC16433@yilunxu-OptiPlex-7050> <20200929012323.GD16433@yilunxu-OptiPlex-7050> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200929012323.GD16433@yilunxu-OptiPlex-7050> Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org Hi Xu, On Tue, Sep 29, 2020 at 09:23:23AM +0800, Xu Yilun wrote: > Hi moritz: > > On Sun, Sep 27, 2020 at 04:36:47PM +0800, Xu Yilun wrote: > > Hi Greg, > > > > On Sun, Sep 27, 2020 at 09:54:01AM +0200, Greg KH wrote: > > > On Sun, Sep 27, 2020 at 03:37:54PM +0800, Xu Yilun wrote: > > > > Hi Greg, > > > > > > > > On Sun, Sep 27, 2020 at 07:51:08AM +0200, Greg KH wrote: > > > > > On Sat, Sep 26, 2020 at 12:22:19PM -0700, Moritz Fischer wrote: > > > > > > Hi Greg, > > > > > > > > > > > > On Sat, Sep 26, 2020 at 08:09:13AM +0200, Greg KH wrote: > > > > > > > On Sat, Sep 26, 2020 at 10:23:46AM +0800, Xu Yilun wrote: > > > > > > > > Hi greg, > > > > > > > > > > > > > > > > About the bus naming, I summarized some questions we've discussed to check > > > > > > > > with you. See inline. > > > > > > > > > > > > > > > > On Thu, Sep 24, 2020 at 10:27:00AM -0700, Moritz Fischer wrote: > > > > > > > > > Hi Xu, > > > > > > > > > > > > > > > > > > On Fri, Sep 25, 2020 at 12:59:57AM +0800, Xu Yilun wrote: > > > > > > > > > > Now the DFL device drivers could be made as independent modules and put > > > > > > > > > > in different subsystems according to their functionalities. So the name > > > > > > > > > > should be descriptive and unique in the whole kernel. > > > > > > > > > > > > > > > > > > > > The patch changes the naming of dfl bus related structures, functions, > > > > > > > > > > APIs and documentations. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Xu Yilun > > > > > > > > > > --- > > > > > > > > > > Documentation/ABI/testing/sysfs-bus-dfl | 15 -- > > > > > > > > > > Documentation/ABI/testing/sysfs-bus-fpga-dfl | 15 ++ > > > > > > > > > > MAINTAINERS | 2 +- > > > > > > > > > > drivers/fpga/dfl.c | 254 ++++++++++++++------------- > > > > > > > > > > drivers/fpga/dfl.h | 77 ++++---- > > > > > > > > > > 5 files changed, 184 insertions(+), 179 deletions(-) > > > > > > > > > > delete mode 100644 Documentation/ABI/testing/sysfs-bus-dfl > > > > > > > > > > create mode 100644 Documentation/ABI/testing/sysfs-bus-fpga-dfl > > > > > > > > > > > > > > > > > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-dfl b/Documentation/ABI/testing/sysfs-bus-dfl > > > > > > > > > > deleted file mode 100644 > > > > > > > > > > index 23543be..0000000 > > > > > > > > > > --- a/Documentation/ABI/testing/sysfs-bus-dfl > > > > > > > > > > +++ /dev/null > > > > > > > > > > @@ -1,15 +0,0 @@ > > > > > > > > > > -What: /sys/bus/dfl/devices/dfl_dev.X/type > > > > > > > > > > -Date: Aug 2020 > > > > > > > > > > -KernelVersion: 5.10 > > > > > > > > > > -Contact: Xu Yilun > > > > > > > > > > -Description: Read-only. It returns type of DFL FIU of the device. Now DFL > > > > > > > > > > - supports 2 FIU types, 0 for FME, 1 for PORT. > > > > > > > > > > - Format: 0x%x > > > > > > > > > > - > > > > > > > > > > -What: /sys/bus/dfl/devices/dfl_dev.X/feature_id > > > > > > > > > > -Date: Aug 2020 > > > > > > > > > > -KernelVersion: 5.10 > > > > > > > > > > -Contact: Xu Yilun > > > > > > > > > > -Description: Read-only. It returns feature identifier local to its DFL FIU > > > > > > > > > > - type. > > > > > > > > > > - Format: 0x%x > > > > > > > > > > > > > > > > > > You're changing userland facing ABI. I think that's something to avoid, > > > > > > > > > please check with Greg on the rules since this hasn't been in a release yet. > > > > > > > > > > > > > > > > > > > > > > > > > I'm going to change the name of bus stuff for other subsystems, to be > > > > > > > > aligned, I also consider change the bus_type.name and dfl dev_name. But > > > > > > > > it will cause the changing of user ABIs. No user case for these user ABI > > > > > > > > now cause they are just queued, is it good I change them? > > > > > > > > > > > > > > Why change the user name here? No need for that, right? Unless you > > > > > > > really want to, and think that no one will notice. If so, fine, change > > > > > > > them :) > > > > > > > > > > > > Let's leave it as is -- An FPGA is one possible implementation and as for > > > > > > other buses, you wouldn't call it fpga-usb or usb-fpga just because the > > > > > > USB bus is implemented in an FPGA if it behaves like a normal USB bus. > > > > > > Having an ASIC based DFL bus show up under dfl-fpga / fpga-dfl in sysfs > > > > > > would be super confusing. > > > > I thought we have consensus that "dfl" could be used out of fpga domain. > > And we are all good that we keep the user ABIs & the bus name - "dfl", so "dfl" > > is good as a global name from linux user's point of view, is it? > > > > But why we reject the "dfl" in kernel code domain? I thought it is very > > similar situation. > > > > > > I think we have 2 options, to make the dfl self-consistent: > > > > 1. "dfl-fpga" for everything - bus name, user ABIs, structures & APIs for > > other kernel subsystems. Then we lose the chance to support ASIC based DFL, > > it would be hard if we change user ABIs later. > > > > 2. "dfl" for everything. > > > > BTW, no ASIC based DFL devices in kernel today. > > > > I fully understand the word "naming is hard" now, help me :) > > Seems now we have different opinions on this: > > - Hao thinks self-consistent is important to dfl framework. Agreed. I mostly care about userspace facing ABI, though. > - "dfl" for everything seems not preferable to Greg. Maybe now that we re-explained, we can take another look at that? > - From your previous mail, I assume you prefer to keep the bus name as "dfl" > but change the stuff for other subsystem, is it? I mostly think we should keep DFL generic where it touches userspace and defines ABI, since we cannot change it afterwards. I rest my point with the bus being independent of FPGAs despite the FPGA being the (currently) only user. > So I got a little stuck here. > > Do you think "dfl-fpga" for everything would be an acceptable solution > for you? I just think it doesn't make a lot of sense to call it fpga-dfl or dfl-fpga. But if everyone else disagrees ... naming is hard :-) Cheers, Moritz