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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 8ABE3C4361B for ; Tue, 2 Mar 2021 08:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F3D76146D for ; Tue, 2 Mar 2021 08:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1837129AbhCBHeA (ORCPT ); Tue, 2 Mar 2021 02:34:00 -0500 Received: from mxout70.expurgate.net ([194.37.255.70]:41177 "EHLO mxout70.expurgate.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347607AbhCBHHN (ORCPT ); Tue, 2 Mar 2021 02:07:13 -0500 Received: from [127.0.0.1] (helo=localhost) by relay.expurgate.net with smtp (Exim 4.90) (envelope-from ) id 1lGz4z-00043R-4L; Tue, 02 Mar 2021 08:04:25 +0100 Received: from [195.243.126.94] (helo=securemail.tdt.de) by relay.expurgate.net with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90) (envelope-from ) id 1lGz4x-0001Ps-Gy; Tue, 02 Mar 2021 08:04:23 +0100 Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id 0AE98240041; Tue, 2 Mar 2021 08:04:23 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id 5CD2C240040; Tue, 2 Mar 2021 08:04:22 +0100 (CET) Received: from mail.dev.tdt.de (localhost [IPv6:::1]) by mail.dev.tdt.de (Postfix) with ESMTP id DE26A20043; Tue, 2 Mar 2021 08:04:20 +0100 (CET) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 02 Mar 2021 08:04:20 +0100 From: Martin Schiller To: Xie He Cc: Jakub Kicinski , Leon Romanovsky , "David S. Miller" , Linux X25 , Linux Kernel Network Developers , LKML , Krzysztof Halasa , Jonathan Corbet , linux-doc@vger.kernel.org Subject: Re: [PATCH net-next RFC v4] net: hdlc_x25: Queue outgoing LAPB frames Organization: TDT AG In-Reply-To: References: <20210216201813.60394-1-xie.he.0141@gmail.com> <20210219103948.6644e61f@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <906d8114f1965965749f1890680f2547@dev.tdt.de> Message-ID: <41b77b1c3cf1bb7a51b750faf23900ef@dev.tdt.de> X-Sender: ms@dev.tdt.de User-Agent: Roundcube Webmail/1.3.16 X-purgate: clean X-purgate-ID: 151534::1614668664-00002CDB-8FE715EC/0/0 X-purgate-type: clean Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-03-01 09:56, Xie He wrote: > On Sun, Feb 28, 2021 at 10:56 PM Martin Schiller wrote: >> >> >> Also, I have a hard time assessing if such a wrap is really >> >> enforceable. >> > >> > Sorry. I don't understand what you mean. What "wrap" are you referring >> > to? >> >> I mean the change from only one hdlc interface to both hdlc and >> hdlc_x25. >> >> I can't estimate how many users are out there and how their setup >> looks >> like. > > I'm also thinking about solving this issue by adding new APIs to the > HDLC subsystem (hdlc_stop_queue / hdlc_wake_queue) for hardware > drivers to call instead of netif_stop_queue / netif_wake_queue. This > way we can preserve backward compatibility. > > However I'm reluctant to change the code of all the hardware drivers > because I'm afraid of introducing bugs, etc. When I look at the code > of "wan/lmc/lmc_main.c", I feel I'm not able to make sure there are no > bugs (related to stop_queue / wake_queue) after my change (and even > before my change, actually). There are even serious style problems: > the majority of its lines are indented by spaces. > > So I don't want to mess with all the hardware drivers. Hardware driver > developers (if they wish to properly support hdlc_x25) should do the > change themselves. This is not a problem for me, because I use my own > out-of-tree hardware driver. However if I add APIs with no user code > in the kernel, other developers may think these APIs are not > necessary. I don't think a change that affects the entire HDLC subsystem is justified, since the actual problem only affects the hdlc_x25 area. The approach with the additional hdlc_x25 is clean and purposeful and I personally could live with it. I just don't see myself in the position to decide such a change at the moment. @Jakub: What is your opinion on this.