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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 99D06C2BA83 for ; Fri, 14 Feb 2020 15:10:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D85724650 for ; Fri, 14 Feb 2020 15:10:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729470AbgBNPKM (ORCPT ); Fri, 14 Feb 2020 10:10:12 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:46530 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729278AbgBNPKM (ORCPT ); Fri, 14 Feb 2020 10:10:12 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 9358B295D01 Subject: Re: [PATCH] platform/chrome: cros_ec_rpmsg: Fix race with host event. To: Pi-Hsun Shih Cc: Benson Leung , Guenter Roeck , open list References: <20200214082638.92070-1-pihsun@chromium.org> From: Enric Balletbo i Serra Message-ID: <83b03af1-5518-599a-3f82-ee204992edbf@collabora.com> Date: Fri, 14 Feb 2020 16:10:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20200214082638.92070-1-pihsun@chromium.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pi-Hsun, On 14/2/20 9:26, Pi-Hsun Shih wrote: > Host event can be sent by remoteproc by any time, and > cros_ec_rpmsg_callback would be called after cros_ec_rpmsg_create_ept. > But the cros_ec_device is initialized after that, which cause host event > handler to use cros_ec_device that are not initialized properly yet. > I don't have the hardware to test but, can't we call first cros_ec_register and then cros_ec_rpmsg_create_ept? Start receiving driver callbacks before finishing to probe the drivers itself sounds weird to me. Thanks, Enric > Fix this by don't schedule host event handler before cros_ec_register > returns. Instead, remember that we have a pending host event, and > schedule host event handler after cros_ec_register. > > Fixes: 71cddb7097e2 ("platform/chrome: cros_ec_rpmsg: Fix race with host command when probe failed.") > Signed-off-by: Pi-Hsun Shih > --- > drivers/platform/chrome/cros_ec_rpmsg.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chrome/cros_ec_rpmsg.c > index dbc3f5523b83..7e8629e3db74 100644 > --- a/drivers/platform/chrome/cros_ec_rpmsg.c > +++ b/drivers/platform/chrome/cros_ec_rpmsg.c > @@ -44,6 +44,8 @@ struct cros_ec_rpmsg { > struct completion xfer_ack; > struct work_struct host_event_work; > struct rpmsg_endpoint *ept; > + bool has_pending_host_event; > + bool probe_done; > }; > > /** > @@ -177,7 +179,14 @@ static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, > memcpy(ec_dev->din, resp->data, len); > complete(&ec_rpmsg->xfer_ack); > } else if (resp->type == HOST_EVENT_MARK) { > - schedule_work(&ec_rpmsg->host_event_work); > + /* > + * If the host event is sent before cros_ec_register is > + * finished, queue the host event. > + */ > + if (ec_rpmsg->probe_done) > + schedule_work(&ec_rpmsg->host_event_work); > + else > + ec_rpmsg->has_pending_host_event = true; > } else { > dev_warn(ec_dev->dev, "rpmsg received invalid type = %d", > resp->type); > @@ -240,6 +249,11 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) > return ret; > } > > + ec_rpmsg->probe_done = true; > + > + if (ec_rpmsg->has_pending_host_event) > + schedule_work(&ec_rpmsg->host_event_work); > + > return 0; > } > > > base-commit: b19e8c68470385dd2c5440876591fddb02c8c402 >