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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 EDA00C3A5A9 for ; Mon, 4 May 2020 11:34:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C84C720752 for ; Mon, 4 May 2020 11:34:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="FGLfEE19" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728794AbgEDLe7 (ORCPT ); Mon, 4 May 2020 07:34:59 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:28530 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728772AbgEDLe4 (ORCPT ); Mon, 4 May 2020 07:34:56 -0400 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 044BX3KE023647; Mon, 4 May 2020 13:34:46 +0200 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=mDjERu7ZrDuEr48yREnU3S3loqh+bWTzk4haAKd7vIA=; b=FGLfEE1959XKXsHX+7yP0ttZYtOUz/ih7s2oG9eTAeJITSb1dKFbDPdoLcC6dIaDtco4 hajFqqOfq8Z+ess0c8ZPvim5ls9s7Ny0KT65cQznhkTMOXZbLSnZfBn8wm+zDWygq3ta khSnB4d2apt91Q9N6AmCYuY5BKp4UvyxMlJNPXazngKKnIgbkZxbL3jmWZVQA/H8Hjt1 4GMiaNzU4mFC1CE22OEuoFh5RAmlEZ+eL+E6UwK30gWISVwBfIPeYZRzKJ6KWTa4dOPo mSyEG7OftVqOoEdrRPoKLR1He+UjtE88pjhoTVzItf0YiksqdG8qsjGOkvS8FBRQ6NUT VQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 30rx08a4ym-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 04 May 2020 13:34:46 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id DD57D10002A; Mon, 4 May 2020 13:34:45 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag3node1.st.com [10.75.127.7]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id C639B2BE223; Mon, 4 May 2020 13:34:45 +0200 (CEST) Received: from lmecxl0889.tpe.st.com (10.75.127.48) by SFHDAG3NODE1.st.com (10.75.127.7) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 4 May 2020 13:34:44 +0200 Subject: Re: [PATCH v3 10/14] remoteproc: Deal with synchronisation when shutting down To: Mathieu Poirier CC: , , , , , , , References: <20200424200135.28825-1-mathieu.poirier@linaro.org> <20200424200135.28825-11-mathieu.poirier@linaro.org> <20200430202312.GE17031@xps15> From: Arnaud POULIQUEN Message-ID: <04b8f860-2b01-7e4f-cdea-08a3cf8af26c@st.com> Date: Mon, 4 May 2020 13:34:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200430202312.GE17031@xps15> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.48] X-ClientProxiedBy: SFHDAG7NODE2.st.com (10.75.127.20) To SFHDAG3NODE1.st.com (10.75.127.7) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-05-04_06:2020-05-04,2020-05-04 signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/30/20 10:23 PM, Mathieu Poirier wrote: > On Wed, Apr 29, 2020 at 10:19:49AM +0200, Arnaud POULIQUEN wrote: >> >> >> On 4/24/20 10:01 PM, Mathieu Poirier wrote: >>> The remoteproc core must not allow function rproc_shutdown() to >>> proceed if currently synchronising with a remote processor and >>> the synchronisation operations of that remote processor does not >>> support it. Also part of the process is to set the synchronisation >>> flag so that the remoteproc core can make the right decisions when >>> restarting the system. >>> >>> Signed-off-by: Mathieu Poirier >>> --- >>> drivers/remoteproc/remoteproc_core.c | 32 ++++++++++++++++++++++++ >>> drivers/remoteproc/remoteproc_internal.h | 7 ++++++ >>> 2 files changed, 39 insertions(+) >>> >>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c >>> index 3a84a38ba37b..48afa1f80a8f 100644 >>> --- a/drivers/remoteproc/remoteproc_core.c >>> +++ b/drivers/remoteproc/remoteproc_core.c >>> @@ -1849,6 +1849,27 @@ int rproc_boot(struct rproc *rproc) >>> } >>> EXPORT_SYMBOL(rproc_boot); >>> >>> +static bool rproc_can_shutdown(struct rproc *rproc) >>> +{ >>> + /* >>> + * The remoteproc core is the lifecycle manager, no problem >>> + * calling for a shutdown. >>> + */ >>> + if (!rproc_needs_syncing(rproc)) >>> + return true; >>> + >>> + /* >>> + * The remoteproc has been loaded by another entity (as per above >>> + * condition) and the platform code has given us the capability >>> + * of stopping it. >>> + */ >>> + if (rproc->sync_ops->stop) >>> + return true; >> >> This means that if rproc->sync_ops->stop is null rproc_stop_subdevices will not >> be called? seems not symmetric with the start sequence. > > If rproc->sync_ops->stop is not provided then the remoteproc core can't stop the > remote processor at all after it has synchronised with it. If a usecase > requires some kind of soft reset then a stop() function that uses a mailbox > notification or some other mechanism can be provided to tell the remote > processor to put itself back in startup mode again. > > Is this fine with you or there is still something I don't get? My point here is more around the subdevices. But perhaps i missed something... In rproc_start rproc_start_subdevices is called, even if sync_start is null. But in rproc_shutdown rproc_stop is not called, if sync_ops->stop is null. So rproc_stop_subdevices is not called in this case. Then if sync_flags.after_stop is false, it looks like that something will go wrong at next start. > >> Probably not useful to test it here as condition is already handled in rproc_stop_device... >> >> Regards >> Arnaud >>> + >>> + /* Any other condition should not be allowed */ >>> + return false; >>> +} >>> + >>> /** >>> * rproc_shutdown() - power off the remote processor >>> * @rproc: the remote processor >>> @@ -1879,6 +1900,9 @@ void rproc_shutdown(struct rproc *rproc) >>> return; >>> } >>> >>> + if (!rproc_can_shutdown(rproc)) >>> + goto out; >>> + >>> /* if the remote proc is still needed, bail out */ >>> if (!atomic_dec_and_test(&rproc->power)) >>> goto out; >>> @@ -1898,6 +1922,14 @@ void rproc_shutdown(struct rproc *rproc) >>> kfree(rproc->cached_table); >>> rproc->cached_table = NULL; >>> rproc->table_ptr = NULL; >>> + >>> + /* >>> + * The remote processor has been switched off - tell the core what >>> + * operation to use from hereon, i.e whether an external entity will >>> + * reboot the remote processor or it is now the remoteproc core's >>> + * responsability. >>> + */ >>> + rproc_set_sync_flag(rproc, RPROC_SYNC_STATE_SHUTDOWN); >>> out: >>> mutex_unlock(&rproc->lock); >>> } >>> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h >>> index 61500981155c..7dcc0a26892b 100644 >>> --- a/drivers/remoteproc/remoteproc_internal.h >>> +++ b/drivers/remoteproc/remoteproc_internal.h >>> @@ -27,6 +27,9 @@ struct rproc_debug_trace { >>> /* >>> * enum rproc_sync_states - remote processsor sync states >>> * >>> + * @RPROC_SYNC_STATE_SHUTDOWN state to use after the remoteproc core >>> + * has shutdown (rproc_shutdown()) the >>> + * remote processor. >>> * @RPROC_SYNC_STATE_CRASHED state to use after the remote processor >>> * has crashed but has not been recovered by >>> * the remoteproc core yet. >>> @@ -36,6 +39,7 @@ struct rproc_debug_trace { >>> * operation to use. >>> */ >>> enum rproc_sync_states { >>> + RPROC_SYNC_STATE_SHUTDOWN, >>> RPROC_SYNC_STATE_CRASHED, >>> }; >>> >>> @@ -43,6 +47,9 @@ static inline void rproc_set_sync_flag(struct rproc *rproc, >>> enum rproc_sync_states state) >>> { >>> switch (state) { >>> + case RPROC_SYNC_STATE_SHUTDOWN: >>> + rproc->sync_with_rproc = rproc->sync_flags.after_stop; >>> + break; >>> case RPROC_SYNC_STATE_CRASHED: >>> rproc->sync_with_rproc = rproc->sync_flags.after_crash; >>> break; >>>