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 CBD3CC33CA1 for ; Wed, 5 Feb 2020 09:06:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A768C20659 for ; Wed, 5 Feb 2020 09:06:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728129AbgBEJGW (ORCPT ); Wed, 5 Feb 2020 04:06:22 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:50466 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727459AbgBEJGW (ORCPT ); Wed, 5 Feb 2020 04:06:22 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id DF1EB2756E6 Subject: Re: [PATCH v6] platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW To: Gwendal Grignou , Marek Szyprowski Cc: Yicheng Li , LKML , Benson Leung , Guenter Roeck , Lee Jones , Andy Shevchenko , Jonathan Cameron , Evan Green , Rushikesh S Kadam , Thomas Gleixner References: <20200203225356.203946-1-yichengli@chromium.org> <54cbade6-c552-4877-a8d7-d2be9930cefd@samsung.com> From: Enric Balletbo i Serra Message-ID: Date: Wed, 5 Feb 2020 10:06:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: 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, On 4/2/20 21:40, Gwendal Grignou wrote: > Reviewed-by: Gwendal Grignou > > On Mon, Feb 3, 2020 at 11:30 PM Marek Szyprowski > wrote: >> >> Hi >> >> On 03.02.2020 23:53, Yicheng Li wrote: >>> RO and RW of EC may have different EC protocol version. If EC transitions >>> between RO and RW, but AP does not reboot (this is true for fingerprint >>> microcontroller / cros_fp, but not true for main ec / cros_ec), the AP >>> still uses the protocol version queried before transition, which can >>> cause problems. In the case of fingerprint microcontroller, this causes >>> AP to send the wrong version of EC_CMD_GET_NEXT_EVENT to RO in the >>> interrupt handler, which in turn prevents RO to clear the interrupt >>> line to AP, in an infinite loop. >>> >>> Once an EC_HOST_EVENT_INTERFACE_READY is received, we know that there >>> might have been a transition between RO and RW, so re-query the protocol. >>> >>> Signed-off-by: Yicheng Li >> >> Tested-by: Marek Szyprowski >> >> Works fine on Samsung Exynos-based Chromebooks: Snow, Peach-Pit and >> Peach-Pi. >> Thanks, we will pick this patch once 5.6-rc1 is out. For my own reference: Acked-for-chrome-platform: Enric Balletbo i Serra >>> --- >>> Hi Enric and Marek, >>> >>>> This patch landed recently in linux-next as commit >>>> 241a69ae8ea8e2defec751fe55dac1287aa044b8. Sadly, it causes following >>>> kernel oops on any key press on Samsung Exynos-based Chromebooks (Snow, >>>> Peach-Pit and Peach-Pi): >>> >>>> Many thanks for report the issue, we will take a look ASAP and revert >>>> this commit meanwhile. >>> >>>> Simply removing the BUG_ON() from cros_ec_get_host_event() function >>>> fixes the issue, but I don't know the protocol details to judge if this >>>> is the correct way of fixing it. >>> The issue was those Samsung Chromebooks (Snow, Peach-Pit and Peach-Pi) >>> do not support mkbp events, yet we applied the same thing to them, which >>> we shouldn't. This v6 should fix it: I Just added a check >>> >>> if (ec_dev->mkbp_event_supported) >>> >>> in cros_ec_register(). >>> >>> >>> >>> drivers/platform/chrome/cros_ec.c | 29 +++++++++++++++++++++ >>> include/linux/platform_data/cros_ec_proto.h | 3 +++ >>> 2 files changed, 32 insertions(+) >>> >>> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c >>> index 9b2d07422e17..f16804db805b 100644 >>> --- a/drivers/platform/chrome/cros_ec.c >>> +++ b/drivers/platform/chrome/cros_ec.c >>> @@ -104,6 +104,23 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) >>> return ret; >>> } >>> >>> +static int cros_ec_ready_event(struct notifier_block *nb, >>> + unsigned long queued_during_suspend, void *_notify) >>> +{ >>> + struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, >>> + notifier_ready); >>> + u32 host_event = cros_ec_get_host_event(ec_dev); >>> + >>> + if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) { >>> + mutex_lock(&ec_dev->lock); >>> + cros_ec_query_all(ec_dev); >>> + mutex_unlock(&ec_dev->lock); >>> + return NOTIFY_OK; >>> + } >>> + >>> + return NOTIFY_DONE; >>> +} >>> + >>> /** >>> * cros_ec_register() - Register a new ChromeOS EC, using the provided info. >>> * @ec_dev: Device to register. >>> @@ -201,6 +218,18 @@ int cros_ec_register(struct cros_ec_device *ec_dev) >>> dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", >>> err); >>> >>> + if (ec_dev->mkbp_event_supported) { >>> + /* >>> + * Register the notifier for EC_HOST_EVENT_INTERFACE_READY >>> + * event. >>> + */ >>> + ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; >>> + err = blocking_notifier_chain_register( >>> + &ec_dev->event_notifier, &ec_dev->notifier_ready); >>> + if (err) >>> + return err; >>> + } >>> + >>> dev_info(dev, "Chrome EC device registered\n"); >>> >>> return 0; >>> diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h >>> index 0d4e4aaed37a..a1c545c464e7 100644 >>> --- a/include/linux/platform_data/cros_ec_proto.h >>> +++ b/include/linux/platform_data/cros_ec_proto.h >>> @@ -121,6 +121,8 @@ struct cros_ec_command { >>> * @event_data: Raw payload transferred with the MKBP event. >>> * @event_size: Size in bytes of the event data. >>> * @host_event_wake_mask: Mask of host events that cause wake from suspend. >>> + * @notifier_ready: The notifier_block to let the kernel re-query EC >>> + * communication protocol when the EC sends EC_HOST_EVENT_INTERFACE_READY. >>> * @ec: The platform_device used by the mfd driver to interface with the >>> * main EC. >>> * @pd: The platform_device used by the mfd driver to interface with the >>> @@ -161,6 +163,7 @@ struct cros_ec_device { >>> int event_size; >>> u32 host_event_wake_mask; >>> u32 last_resume_result; >>> + struct notifier_block notifier_ready; >>> >>> /* The platform devices used by the mfd driver */ >>> struct platform_device *ec; >> >> Best regards >> -- >> Marek Szyprowski, PhD >> Samsung R&D Institute Poland >>