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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 8D656C433DF for ; Wed, 19 Aug 2020 06:40:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CD52207DA for ; Wed, 19 Aug 2020 06:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726698AbgHSGk3 (ORCPT ); Wed, 19 Aug 2020 02:40:29 -0400 Received: from muru.com ([72.249.23.125]:40890 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726840AbgHSGk2 (ORCPT ); Wed, 19 Aug 2020 02:40:28 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id C82A6807A; Wed, 19 Aug 2020 06:40:27 +0000 (UTC) Date: Wed, 19 Aug 2020 09:40:55 +0300 From: Tony Lindgren To: Jiri Slaby Cc: Greg Kroah-Hartman , Gregory CLEMENT , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Shevchenko Subject: Re: [PATCH] n_gsm: Fix write handling for zero bytes written Message-ID: <20200819064055.GV2994@atomide.com> References: <20200817135454.28505-1-tony@atomide.com> <1b8538a8-d8b6-4287-36e1-aa1e0863ff2d@kernel.org> <20200818095609.GQ2994@atomide.com> <20200818104714.GR2994@atomide.com> <34dd61d2-01c3-dcc1-21bd-494eb90759ac@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <34dd61d2-01c3-dcc1-21bd-494eb90759ac@kernel.org> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org * Jiri Slaby [200819 06:20]: > On 18. 08. 20, 12:47, Tony Lindgren wrote: > > * Jiri Slaby [200818 10:14]: > >> On 18. 08. 20, 11:56, Tony Lindgren wrote: > >>> Hi, > >>> > >>> * Jiri Slaby [200818 08:24]: > >>>> On 17. 08. 20, 15:54, Tony Lindgren wrote: > >>>>> If write returns zero we currently end up removing the message > >>>>> from the queue. Instead of removing the message, we want to just > >>>>> break out of the loop just like we already do for error codes. > >>>> > >>>> When exactly does the only writer (gsmld_output) return zero for > >>>> non-zero len parameter? > >>> > >>> I ran into this when testing with the WIP serial core PM runtime > >>> changes from Andy Shevchenko earlier. If there are also other > >>> cases where we have serial drivers return 0, I don't know about > >>> them. > >> > >> Sorry, I don't understand: my gsmld_output() ignores the return value > >> from drivers' write and returns something greater than zero or a > >> negative error. What tree/SHA do you run? > > > > Oh right, good catch. I also had my WIP serdev-ngsm patches applied > > that uses gsm_serdev_output() and returns the bytes written. Andy's > > patches do not touch n_gsm.c. > > > > Hmm sounds like we should also start returning value also from > > gsmld_output()? Any objections to making that change? > > No objections here. OK thanks, I'll post an updated patch. Regards, Tony