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=-11.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 4975DC433E7 for ; Sun, 11 Oct 2020 00:18:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E167F2158C for ; Sun, 11 Oct 2020 00:18:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="frNCU2MP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729470AbgJKASt (ORCPT ); Sat, 10 Oct 2020 20:18:49 -0400 Received: from m42-4.mailgun.net ([69.72.42.4]:55670 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726473AbgJKASt (ORCPT ); Sat, 10 Oct 2020 20:18:49 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1602375527; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=GQIDbu7+fq9cMGVT0omtkeQCnmv9hNu0TbjGuYauBis=; b=frNCU2MP4HYnaK8F7r8bmWOpLlY3PGrJW2Jr9/rvtbk5/UuFmvyw3/C06qqbC9WFW2Ozjbq2 pApc1wN3aCdVZhUuSkrLrbI6wuPRtiqLSOrN5PWGYCx5t6ME1FwdHoXvbuDx6Z8Upy/VX3Dn DZQtYLeiLnWwRN5o0r9sjEQNxBw= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-east-1.postgun.com with SMTP id 5f824f36aad2c3cd1c8e7fc0 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Sun, 11 Oct 2020 00:17:58 GMT Sender: mgautam=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C2C59C433FF; Sun, 11 Oct 2020 00:17:57 +0000 (UTC) Received: from [192.168.1.8] (unknown [223.230.69.105]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mgautam) by smtp.codeaurora.org (Postfix) with ESMTPSA id CBB27C433CB; Sun, 11 Oct 2020 00:17:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org CBB27C433CB Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=mgautam@codeaurora.org Subject: Re: [PATCH v1 10/10] bus: mhi: core: Mark device inactive soon after host issues a shutdown To: Bhaumik Bhatt , manivannan.sadhasivam@linaro.org Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org, jhugo@codeaurora.org, linux-kernel@vger.kernel.org References: <1600480955-16827-1-git-send-email-bbhatt@codeaurora.org> <1600480955-16827-11-git-send-email-bbhatt@codeaurora.org> From: Manu Gautam Message-ID: <0bdbe5b1-d26c-1bab-14d3-95015ee96e51@codeaurora.org> Date: Sun, 11 Oct 2020 05:47:49 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <1600480955-16827-11-git-send-email-bbhatt@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 9/19/2020 7:32 AM, Bhaumik Bhatt wrote: > Clients on the host may see the device in an active state for a short > period of time after the host detects a device error or power down. What scenario is referred as 'device error' here? And power down is the non-graceful power_down by controller? > Prevent any further host activity which could lead to race conditions > or multiple callbacks to the controller or any timeouts seen by > clients attempting to push data as they must be notified of the host > intent sooner rather than later. This also allows the host and device > states to be in sync with one another and prevents unnecessary host > operations. > > Signed-off-by: Bhaumik Bhatt > --- > drivers/bus/mhi/core/main.c | 4 ++++ > drivers/bus/mhi/core/pm.c | 31 +++++++++++++++++++------------ > 2 files changed, 23 insertions(+), 12 deletions(-) > > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > index 1c8e332..5ec89e9 100644 > --- a/drivers/bus/mhi/core/main.c > +++ b/drivers/bus/mhi/core/main.c > @@ -400,6 +400,10 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv) > > /* If device supports RDDM don't bother processing SYS error */ > if (mhi_cntrl->rddm_image) { > + /* host may be performing a device power down already */ > + if (!mhi_is_active(mhi_cntrl)) > + goto exit_intvec; > + > if (mhi_cntrl->ee == MHI_EE_RDDM && mhi_cntrl->ee != ee) { > /* prevent clients from queueing any more packets */ > write_lock_irq(&mhi_cntrl->pm_lock); > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index 16c04ab..4e2cb41 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -469,15 +469,10 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, > write_lock_irq(&mhi_cntrl->pm_lock); > prev_state = mhi_cntrl->pm_state; > cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state); > - if (cur_state == transition_state) { > - mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION; > + if (cur_state == MHI_PM_SYS_ERR_PROCESS) > mhi_cntrl->dev_state = MHI_STATE_RESET; > - } > write_unlock_irq(&mhi_cntrl->pm_lock); > > - /* Wake up threads waiting for state transition */ > - wake_up_all(&mhi_cntrl->state_event); > - > if (cur_state != transition_state) { > dev_err(dev, "Failed to transition to state: %s from: %s\n", > to_mhi_pm_state_str(transition_state), > @@ -486,6 +481,11 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, > return; > } > > + mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION; > + > + /* Wake up threads waiting for state transition */ > + wake_up_all(&mhi_cntrl->state_event); > + > /* Trigger MHI RESET so that the device will not access host memory */ > if (MHI_REG_ACCESS_VALID(prev_state)) { > u32 in_reset = -1; > @@ -1051,22 +1051,29 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) > enum dev_st_transition next_state = DEV_ST_TRANSITION_DISABLE; > struct device *dev = &mhi_cntrl->mhi_dev->dev; > > + mutex_lock(&mhi_cntrl->pm_mutex); > + write_lock_irq(&mhi_cntrl->pm_lock); > + > /* If it's not a graceful shutdown, force MHI to linkdown state */ > if (!graceful) { > - mutex_lock(&mhi_cntrl->pm_mutex); > - write_lock_irq(&mhi_cntrl->pm_lock); > cur_state = mhi_tryset_pm_state(mhi_cntrl, > MHI_PM_LD_ERR_FATAL_DETECT); > - write_unlock_irq(&mhi_cntrl->pm_lock); > - mutex_unlock(&mhi_cntrl->pm_mutex); > - if (cur_state != MHI_PM_LD_ERR_FATAL_DETECT) > + if (cur_state != MHI_PM_LD_ERR_FATAL_DETECT) { > dev_dbg(dev, "Failed to move to state: %s from: %s\n", > to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT), > to_mhi_pm_state_str(mhi_cntrl->pm_state)); > - else > + } else { > next_state = DEV_ST_TRANSITION_FATAL; > + wake_up_all(&mhi_cntrl->state_event); > + } > } > > + /* mark device inactive to avoid any further host processing */ > + mhi_cntrl->dev_state = MHI_STATE_RESET; > + > + write_unlock_irq(&mhi_cntrl->pm_lock); > + mutex_unlock(&mhi_cntrl->pm_mutex); > + > mhi_queue_state_transition(mhi_cntrl, next_state); > > /* Wait for shutdown to complete */ -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project