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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 47EA0C04FF3 for ; Mon, 24 May 2021 04:37:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19FE6610CE for ; Mon, 24 May 2021 04:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232130AbhEXEjQ (ORCPT ); Mon, 24 May 2021 00:39:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbhEXEjO (ORCPT ); Mon, 24 May 2021 00:39:14 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3456CC061574 for ; Sun, 23 May 2021 21:37:46 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id v13-20020a17090abb8db029015f9f7d7290so812753pjr.0 for ; Sun, 23 May 2021 21:37:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=MDE07gsiuD4M3r2LCEJykHaQUxtgYgyzLwjRG2xiWSo=; b=cMlNRaFVHxk/Vg2m4FWR7arQ/ghKts+RBvLvpeQcGyy25qofos/zvz9gUv7jDeVjza 93RZUp5BiFbSqTrO+NUWRNsYj8cyBstCJBjhS3klDTdiKbCqN8gQYBgUNRJElP+C925B ozyW+qN+zvi6L7UdnFuG8PIldHGPc/9jpIwBkA1t/2/3guTMpuunG+456UxWgZ7FDSuU PKXM46qji8s89yr0dCU8ihrFl+w/q4zR6/zhs4tvktAHndJV9fX6fUWVzafwUBwIk7Pl mkBAvXkgpVAt29Iz5EdNRiU+cSC3mZFHmUm6rQPX0IhZwaUVrnJ9CF9CJU0d8yU9TVjs mBmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=MDE07gsiuD4M3r2LCEJykHaQUxtgYgyzLwjRG2xiWSo=; b=ZJMr3v5JqbtQhSHFm4l9uQ0dB8nu03YgF4L4tYKvvrS4+46CShARgLdJTJ2UtAbgtn WPfrDst+o7XrNC9eFA3vrQJur6lNOmRWkpTHyhIlJ4jYiTKhQmiwsox8VdrpFmz2V7PF bwrj4h/+MbG0U8Cjw1UEUtW8Xj6uuGWqDMiB87gLjcIaF+1ufDd5aZk2Bo5PAqQKwK3y D8+FfdkLJv9AvFQknSEnj+e4fJNd4SVXAIc8/+3j6G1+WXT9lohjX5GtJyVZ0+FnwxSr bX/2KfaNqHb5YIkCD2LIYjowtoYK3hS4cBpWG3LxSA62XlikMGR0iK1+tPM453bSbnII k/KA== X-Gm-Message-State: AOAM533Zg25mcVvn0i3s+Enbt3m8iZahwOCHuI8tzq+djNL0XRHcmfMU oXyKB2iVVXIu66wqzlpWynPv X-Google-Smtp-Source: ABdhPJy9QPbKkRIFtXdAwMIebxG5sg01nmgnd6EX7GHXpAgjDNbW5i8bMBIDNwjkg/fabwwZYgm8qA== X-Received: by 2002:a17:90a:b38d:: with SMTP id e13mr22456179pjr.222.1621831065632; Sun, 23 May 2021 21:37:45 -0700 (PDT) Received: from work ([120.138.12.48]) by smtp.gmail.com with ESMTPSA id v14sm9680578pfi.25.2021.05.23.21.37.42 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 23 May 2021 21:37:44 -0700 (PDT) Date: Mon, 24 May 2021 10:07:40 +0530 From: Manivannan Sadhasivam To: Baochen Qiang Cc: hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, ath11k@lists.infradead.org, stable@vger.kernel.org Subject: Re: [PATCH v2] bus: mhi: Wait for M2 state during system resume Message-ID: <20210524043740.GC8823@work> References: <20210524040312.14409-1-bqiang@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210524040312.14409-1-bqiang@codeaurora.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 24, 2021 at 12:03:12PM +0800, Baochen Qiang wrote: > During system resume, MHI host triggers M3->M0 transition and then waits > for target device to enter M0 state. Once done, the device queues a state > change event into ctrl event ring and notifies MHI host by raising an > interrupt, where a tasklet is scheduled to process this event. In most cases, > the tasklet is served timely and wait operation succeeds. > > However, there are cases where CPU is busy and cannot serve this tasklet > for some time. Once delay goes long enough, the device moves itself to M1 > state and also interrupts MHI host after inserting a new state change > event to ctrl ring. Later CPU finally has time to process the ring, however > there are two events in it now: > 1. for M3->M0 event, which is processed first as queued first, > tasklet handler updates device state to M0 and wakes up the task, > i.e., the MHI host. > 2. for M0->M1 event, which is processed later, tasklet handler > triggers M1->M2 transition and updates device state to M2 directly, > then wakes up the MHI host(if still sleeping on this wait queue). > Note that although MHI host has been woken up while processing the first > event, it may still has no chance to run before the second event is processed. > In other words, MHI host has to keep waiting till timeout cause the M0 state > has been missed. > > kernel log here: > ... > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.911251] mhi 0000:06:00.0: Entered with PM state: M3, MHI state: M3 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917762] mhi 0000:06:00.0: State change event to state: M0 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917767] mhi 0000:06:00.0: State change event to state: M1 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4338.788231] mhi 0000:06:00.0: Did not enter M0 state, MHI state: M2, PM state: M2 > ... > > Fix this issue by simply adding M2 as a valid state for resume. > > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1 > > Fixes: 0c6b20a1d720 ("bus: mhi: core: Add support for MHI suspend and resume") > Signed-off-by: Baochen Qiang > Reviewed-by: Hemant Kumar Applied to mhi-fixes! Thanks, Mani > --- > drivers/bus/mhi/core/pm.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index e2e59a341fef..59b009a3ee9b 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -934,6 +934,7 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl) > > ret = wait_event_timeout(mhi_cntrl->state_event, > mhi_cntrl->dev_state == MHI_STATE_M0 || > + mhi_cntrl->dev_state == MHI_STATE_M2 || > MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), > msecs_to_jiffies(mhi_cntrl->timeout_ms)); > > -- > 2.25.1 >