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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 E3013C433E7 for ; Fri, 9 Oct 2020 06:40:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F3D522255 for ; Fri, 9 Oct 2020 06:40:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602225638; bh=lqSG5go+7JmxZFOjn/W8DBmDwIQZ3JY5xAi8begoBks=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=eaQo5YBymUZbN5i830CYN6PFwddQtaa23vLtP+1r39/LSCr5Z21UxL0ke9KC7jwSy NaTIS3yG6j36EpAL7FXIxk0qsdtx4/7skyjnlmlTSEWsnYi1aY/CCmbfxoZqW+/hcZ rttKMGVl9JzssV79mx/ojD3s3Z7d0Nstcl6F/kB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725922AbgJIGki (ORCPT ); Fri, 9 Oct 2020 02:40:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:35648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726347AbgJIGkh (ORCPT ); Fri, 9 Oct 2020 02:40:37 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EC78922251; Fri, 9 Oct 2020 06:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602225636; bh=lqSG5go+7JmxZFOjn/W8DBmDwIQZ3JY5xAi8begoBks=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vDL0w9w6GzKo7xhMWhXG65CS3jHEszw++LbmOe2emOoWgY//93x5lFMnIgp/MwC4p tLbPYO/izZ73KveGMX0ty6rjhVTyfk2lBw+NA49YEROWwg5K6BChRDVO/OAtatirgr 7/0RK3LncpqQ/Oo9SN9yvWqhzobTzdA4D4+hqbXc= Date: Fri, 9 Oct 2020 08:41:18 +0200 From: Greg KH To: Xu Yilun Cc: Moritz Fischer , 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: <20201009064118.GA655664@kroah.com> References: <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> <20200929041900.GA113620@archbook> <20201009062059.GB24324@yilunxu-OptiPlex-7050> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201009062059.GB24324@yilunxu-OptiPlex-7050> Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Fri, Oct 09, 2020 at 02:20:59PM +0800, Xu Yilun wrote: > Hi Greg: > > On Mon, Sep 28, 2020 at 09:19:00PM -0700, Moritz Fischer wrote: > > 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 :-) > > Hi Greg, > > We made some re-explanation why "dfl" could be independent of the fpga > subsystem in this mail thread. And now the name "dfl" for all bus stuff is good > to Moritz, Hao & Yilun. Could you help take another look at this? What is "this"? I don't see any fpga patches in my inbox anywhere...