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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 F101BC63798 for ; Tue, 17 Nov 2020 16:59:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB45622447 for ; Tue, 17 Nov 2020 16:59:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728529AbgKQQ7L (ORCPT ); Tue, 17 Nov 2020 11:59:11 -0500 Received: from mga07.intel.com ([134.134.136.100]:43263 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727653AbgKQQ7K (ORCPT ); Tue, 17 Nov 2020 11:59:10 -0500 IronPort-SDR: 0K/fLg12ZJOLMYlowLaCX8O1hiilIwBQy4gsPt8bERS4HZ9CNxDt0jf31UQ/MEOWi1lOOKOaMS 3eCOP8owC+mA== X-IronPort-AV: E=McAfee;i="6000,8403,9808"; a="235110966" X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="235110966" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 08:58:22 -0800 IronPort-SDR: W8mhrInwfX5NO792DuVW7vAbg0zvPzhzo8/psiL3qmOqw1O+Qz1/oOSyOXQf+FMAsh/emuanQf 8fUxurkeaI+w== X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="544123584" Received: from gliakhov-mobl2.ger.corp.intel.com (HELO ubuntu) ([10.252.34.253]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 08:58:20 -0800 Date: Tue, 17 Nov 2020 17:58:16 +0100 From: Guennadi Liakhovetski To: Arnaud POULIQUEN Cc: Mathieu Poirier , "ohad@wizery.com" , "bjorn.andersson@linaro.org" , "linux-remoteproc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v5 8/8] rpmsg: Turn name service into a stand alone driver Message-ID: <20201117165816.GB15538@ubuntu> References: <20201112115115.GA11069@ubuntu> <945f377d-1975-552d-25b2-1dc25d3c3a46@st.com> <2d25d1aa-bd8a-f0db-7888-9f72edc9f687@st.com> <20201116151028.GA1519@ubuntu> <20201116224003.GC3892875@xps15> <50549519-d9ff-9048-a3d8-dab02bfda096@st.com> <20201117160330.GA15538@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 17, 2020 at 05:44:05PM +0100, Arnaud POULIQUEN wrote: > > > On 11/17/20 5:03 PM, Guennadi Liakhovetski wrote: > > On Tue, Nov 17, 2020 at 12:42:30PM +0100, Arnaud POULIQUEN wrote: > > > > [snip] > > > >> diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c > >> index 5bda7cb44618..80c2cc23bada 100644 > >> --- a/drivers/rpmsg/rpmsg_ns.c > >> +++ b/drivers/rpmsg/rpmsg_ns.c > >> @@ -55,6 +55,39 @@ static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void > >> *data, int len, > >> return 0; > >> } > >> > >> +/** > >> + * rpmsg_ns_register_device() - register name service device based on rpdev > >> + * @rpdev: prepared rpdev to be used for creating endpoints > >> + * > >> + * This function wraps rpmsg_register_device() preparing the rpdev for use as > >> + * basis for the rpmsg name service device. > >> + */ > >> +int rpmsg_ns_register_device(struct rpmsg_device *rpdev) > >> +{ > >> +#ifdef MODULES > >> + int ret; > >> + struct module *rpmsg_ns; > >> + > >> + mutex_lock(&module_mutex); > >> + rpmsg_ns = find_module(KBUILD_MODNAME); > >> + mutex_unlock(&module_mutex); > >> + > >> + if (!rpmsg_ns) { > >> + ret = request_module(KBUILD_MODNAME); > > > > Is this code requesting the module in which it is located?.. I must be missing > > something... > > Right this is stupid...Thanks to highlight this! > > That being said, your remark is very interesting: we need to load the module to > access to this function. This means that calling this function ensures that the > module is loaded. In this case no need to add the piece of code to find > module... here is the call stack associated (associated patch is available below): Yes, as I wrote 10 hours ago: > Now, as for how to actually load the > module, I'd really propose to move rpmsg_ns_register_device() into the .c > file and then the problem will be resolved automatically: as a symbol > dependence the module will be loaded whenever another module, calling > rpmsg_ns_register_device() is loaded. Thanks Guennadi > (rpmsg_ns_probe+0x5c/0xe0 [rpmsg_ns]) > [ 11.858748] [] (rpmsg_ns_probe [rpmsg_ns]) from [] > (rpmsg_dev_probe+0x14c/0x1b0 [rpmsg_core]) > [ 11.869047] [] (rpmsg_dev_probe [rpmsg_core]) from [] > (really_probe+0x208/0x4f0) > [ 11.878117] [] (really_probe) from [] > (driver_probe_device+0x78/0x16c) > [ 11.886404] [] (driver_probe_device) from [] > (bus_for_each_drv+0x84/0xd0) > [ 11.894887] [] (bus_for_each_drv) from [] > (__device_attach+0xf0/0x188) > [ 11.903142] [] (__device_attach) from [] > (bus_probe_device+0x84/0x8c) > [ 11.911314] [] (bus_probe_device) from [] > (device_add+0x3b0/0x7b0) > [ 11.919227] [] (device_add) from [] > (rpmsg_register_device+0x54/0x88 [rpmsg_core]) > [ 11.928541] [] (rpmsg_register_device [rpmsg_core]) from > [] (rpmsg_probe+0x298/0x3c8 [virtio_rpmsg_bus]) > [ 11.939748] [] (rpmsg_probe [virtio_rpmsg_bus]) from [] > (virtio_dev_probe+0x1f4/0x2c4) > [ 11.949377] [] (virtio_dev_probe) from [] > (really_probe+0x208/0x4f0) > [ 11.957454] [] (really_probe) from [] > (driver_probe_device+0x78/0x16c) > [ 11.965710] [] (driver_probe_device) from [] > (device_driver_attach+0x58/0x60) > [ 11.974574] [] (device_driver_attach) from [] > (__driver_attach+0xb4/0x154) > [ 11.983177] [] (__driver_attach) from [] > (bus_for_each_dev+0x78/0xc0) > [ 11.991344] [] (bus_for_each_dev) from [] > (bus_add_driver+0x170/0x20c) > [ 11.999600] [] (bus_add_driver) from [] > (driver_register+0x74/0x108) > [ 12.007693] [] (driver_register) from [] > (rpmsg_init+0x10/0x1000 [virtio_rpmsg_bus]) > [ 12.017168] [] (rpmsg_init [virtio_rpmsg_bus]) from [] > (do_one_initcall+0x58/0x2bc) > [ > > This would make the patch very simple. I tested following patch on my platform, > applying it, i do not reproduce the initial issue. > > > diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig > index c3fc75e6514b..1394114782d2 100644 > --- a/drivers/rpmsg/Kconfig > +++ b/drivers/rpmsg/Kconfig > @@ -71,5 +71,6 @@ config RPMSG_VIRTIO > depends on HAS_DMA > select RPMSG > select VIRTIO > + select RPMSG_NS > > endmenu > diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c > index 5bda7cb44618..5867281188de 100644 > --- a/drivers/rpmsg/rpmsg_ns.c > +++ b/drivers/rpmsg/rpmsg_ns.c > @@ -55,6 +55,24 @@ static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void > *data, int len, > return 0; > } > > +/** > + * rpmsg_ns_register_device() - register name service device based on rpdev > + * @rpdev: prepared rpdev to be used for creating endpoints > + * > + * This function wraps rpmsg_register_device() preparing the rpdev for use as > + * basis for the rpmsg name service device. > + */ > +int rpmsg_ns_register_device(struct rpmsg_device *rpdev) > +{ > + strcpy(rpdev->id.name, KBUILD_MODNAME); > + rpdev->driver_override = KBUILD_MODNAME; > + rpdev->src = RPMSG_NS_ADDR; > + rpdev->dst = RPMSG_NS_ADDR; > + > + return rpmsg_register_device(rpdev); > +} > +EXPORT_SYMBOL(rpmsg_ns_register_device); > + > static int rpmsg_ns_probe(struct rpmsg_device *rpdev) > { > struct rpmsg_endpoint *ns_ept; > @@ -80,7 +98,7 @@ static int rpmsg_ns_probe(struct rpmsg_device *rpdev) > } > > static struct rpmsg_driver rpmsg_ns_driver = { > - .drv.name = "rpmsg_ns", > + .drv.name = KBUILD_MODNAME, > .probe = rpmsg_ns_probe, > }; > > @@ -104,5 +122,5 @@ module_exit(rpmsg_ns_exit); > > MODULE_DESCRIPTION("Name service announcement rpmsg Driver"); > MODULE_AUTHOR("Arnaud Pouliquen "); > -MODULE_ALIAS("rpmsg_ns"); > +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); > MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/rpmsg/ns.h b/include/linux/rpmsg/ns.h > index bdc1ea278814..68eac2b42075 100644 > --- a/include/linux/rpmsg/ns.h > +++ b/include/linux/rpmsg/ns.h > @@ -41,21 +41,6 @@ enum rpmsg_ns_flags { > /* Address 53 is reserved for advertising remote services */ > #define RPMSG_NS_ADDR (53) > > -/** > - * rpmsg_ns_register_device() - register name service device based on rpdev > - * @rpdev: prepared rpdev to be used for creating endpoints > - * > - * This function wraps rpmsg_register_device() preparing the rpdev for use as > - * basis for the rpmsg name service device. > - */ > -static inline int rpmsg_ns_register_device(struct rpmsg_device *rpdev) > -{ > - strcpy(rpdev->id.name, "rpmsg_ns"); > - rpdev->driver_override = "rpmsg_ns"; > - rpdev->src = RPMSG_NS_ADDR; > - rpdev->dst = RPMSG_NS_ADDR; > - > - return rpmsg_register_device(rpdev); > -} > +int rpmsg_ns_register_device(struct rpmsg_device *rpdev); > > #endif > > Thanks, > Arnaud > > > > > Thanks > > Guennadi > >