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=-5.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 9B298C55ABD for ; Mon, 9 Nov 2020 08:49:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30074206ED for ; Mon, 9 Nov 2020 08:49:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="HSrBj9bP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729514AbgKIItB (ORCPT ); Mon, 9 Nov 2020 03:49:01 -0500 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:60114 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726127AbgKIItA (ORCPT ); Mon, 9 Nov 2020 03:49:00 -0500 Received: from pps.filterd (m0046037.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0A98mXkK005109; Mon, 9 Nov 2020 09:48:54 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=STMicroelectronics; bh=gswr127pV79PDGvq3mOE0Nu5v+9AQ5VJ4ll6tXITl8E=; b=HSrBj9bPeqqEv1ps/7Nv3wVCcFbHr6JohgyxmLLqbyu3bzBwnWPPadhRhtKi/u6iwkuu Np0ECpmiBcla+VhI3Tm7aC4rQldSWaHM0xtL6mhoBUwAe9vng4kBou0rCjpa4eWzU3uC p58H1Pxyg48XBGjBQnFxRG3Mp2M5qQrx4qPL/W/ghqWJ6AJYSlC8B45DDtak3tm5KDjW wHtIMaw2AH5LedvFtDAy8VlrXtdrgIsLev0Qwv2Nk9N2QSfKBueeEYKmwAG7cmTfr/K1 lQVr2BRMJY89Mwy8pkZG/oCr2y0CQzWOb2QU7kyOGcmxCSWBsa0nD/dFydZCkr686WXd 5A== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 34nj80gucj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 09 Nov 2020 09:48:54 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 893CB100034; Mon, 9 Nov 2020 09:48:53 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag3node1.st.com [10.75.127.7]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 702A6230D43; Mon, 9 Nov 2020 09:48:53 +0100 (CET) Received: from lmecxl0889.lme.st.com (10.75.127.50) by SFHDAG3NODE1.st.com (10.75.127.7) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 9 Nov 2020 09:48:37 +0100 Subject: Re: [PATCH v5 8/8] rpmsg: Turn name service into a stand alone driver To: Mathieu Poirier , Guennadi Liakhovetski CC: "ohad@wizery.com" , "bjorn.andersson@linaro.org" , "linux-remoteproc@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20201105225028.3058818-1-mathieu.poirier@linaro.org> <20201105225028.3058818-9-mathieu.poirier@linaro.org> <20201106131545.GA10889@ubuntu> <20201106140028.GB10889@ubuntu> <20201106175332.GB3203364@xps15> From: Arnaud POULIQUEN Message-ID: Date: Mon, 9 Nov 2020 09:48:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201106175332.GB3203364@xps15> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG4NODE3.st.com (10.75.127.12) To SFHDAG3NODE1.st.com (10.75.127.7) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-09_02:2020-11-05,2020-11-09 signatures=0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guennadi, Mathieu, On 11/6/20 6:53 PM, Mathieu Poirier wrote: > On Fri, Nov 06, 2020 at 03:00:28PM +0100, Guennadi Liakhovetski wrote: >> On Fri, Nov 06, 2020 at 02:15:45PM +0100, Guennadi Liakhovetski wrote: >>> Hi Mathieu, Arnaud, >>> >>> On Thu, Nov 05, 2020 at 03:50:28PM -0700, Mathieu Poirier wrote: >>>> From: Arnaud Pouliquen >>>> >>>> Make the RPMSG name service announcement a stand alone driver so that it >>>> can be reused by other subsystems. It is also the first step in making the >>>> functionatlity transport independent, i.e that is not tied to virtIO. >>> >>> Sorry, I just realised that my testing was incomplete. I haven't tested >>> automatic module loading and indeed it doesn't work. If rpmsg_ns is loaded >>> it probes and it's working, but if it isn't loaded and instead the rpmsg >>> bus driver is probed (e.g. virtio_rpmsg_bus), calling >>> rpmsg_ns_register_device() to create a new rpmsg_ns device doesn't cause >>> rpmsg_ns to be loaded. >> >> A simple fix for that is using MODULE_ALIAS("rpmsg:rpmsg_ns"); in rpmsg_ns.c >> but that alone doesn't fix the problem completely - the module does load then >> but not quickly enough, the NS announcement from the host / remote arrives >> before rpmsg_ns has properly registered. I think the best solution would be >> to link rpmsg_ns.c together with rpmsg_core.c. You'll probably want to keep >> the module name, so you could rename them to just core.c and ns.c. > > I'm pretty sure it is because virtio_device_ready() in rpmsg_probe() is called > before the kernel has finished loading the name space driver. There has to be > a way to prevent that from happening - I will investigate further. Right, no dependency is set so the rpmsg_ns driver is never probed... And name service announcement messages are dropped if the service is not present. if rpmsg_virtio_bus is built-in -> using "select RPMSG_NS" in RPMSG_VIRTIO kconfig should ensure that rpmsg_ns is also built-in if rpmsg_virtio_bus is build as module rpmsg_ns.ko should be loaded first. -> MODULE_SOFTDEP could be used in virtio_rpmsg_bus.c Thanks, Arnaud > > Thanks for reporting this, > Mathieu > >> >> Thanks >> Guennadi