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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3F78C77B7F for ; Wed, 17 May 2023 16:49:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229509AbjEQQt7 (ORCPT ); Wed, 17 May 2023 12:49:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbjEQQt6 (ORCPT ); Wed, 17 May 2023 12:49:58 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A779A40F7; Wed, 17 May 2023 09:49:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684342196; x=1715878196; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=1FDXaOvMiv/7nzig5qwdhuEpYL+zWHcV8CYwzpgWZu4=; b=FauTNvl8g65N5QwNNQrP2udX1mntjz+zn75Jg7fRptXF+FE5yGM2VXNK /I6C3HW7H89wsblJE4R2zpBM/YhKXMYWIE04oibOt5FLc8QPtvaI2fOfr IHcz8PWVJ3zAfQowW6QyxDRqmDwGs6f6oQMLXWb8DWDEJrzaz0R3/RFEa 7Ab8SzuxEbxznBp3AajcfGJpB1+ettkFmlgAtzFf5Y1TLwIEUDsu067VC Ge7h6XtG7qV/kUFJZHfFGdKcePx0wAXYem4eRivApOLusOg2Pz2Fcpf9D v89Lygv4JHLCRb99QbA+pInjXzC0mgZFKp6SqfJtG/RBvMHqwRRXQLNO9 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10713"; a="350649356" X-IronPort-AV: E=Sophos;i="5.99,282,1677571200"; d="scan'208";a="350649356" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2023 09:48:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10713"; a="734764317" X-IronPort-AV: E=Sophos;i="5.99,282,1677571200"; d="scan'208";a="734764317" Received: from pgopdahl-mobl1.amr.corp.intel.com (HELO [10.209.16.196]) ([10.209.16.196]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2023 09:48:48 -0700 Message-ID: <7bcb1ee2-3950-5a43-14ee-5f16942b1eee@linux.intel.com> Date: Wed, 17 May 2023 11:47:20 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.10.0 Subject: Re: [PATCH 1/2] soundwire: qcom: fix unbalanced pm_runtime_put() Content-Language: en-US To: Krzysztof Kozlowski , Vinod Koul , Bard Liao , Sanyog Kale , Andy Gross , Bjorn Andersson , Konrad Dybcio , =?UTF-8?Q?P=c3=a9ter_Ujfalusi?= , Srinivas Kandagatla , Charles Keepax , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <20230517163750.997629-1-krzysztof.kozlowski@linaro.org> From: Pierre-Louis Bossart In-Reply-To: <20230517163750.997629-1-krzysztof.kozlowski@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 5/17/23 11:37, Krzysztof Kozlowski wrote: > This reverts commit 57ed510b0547 ("soundwire: qcom: use > pm_runtime_resume_and_get()") which introduced unbalanced > pm_runtime_put(), when device did not have runtime PM enabled. > > If pm_runtime_resume_and_get() failed with -EACCES, the driver continued > execution and finally called pm_runtime_put_autosuspend(). Since > pm_runtime_resume_and_get() drops the usage counter on every error, this > lead to double decrement of that counter visible in certain debugfs > actions on unattached devices (still in reset state): > > $ cat /sys/kernel/debug/soundwire/master-0-0/sdw:0:0217:f001:00:0/registers > qcom-soundwire 3210000.soundwire-controller: swrm_wait_for_wr_fifo_avail err write overflow > soundwire sdw-master-0: trf on Slave 1 failed:-5 read addr e36 count 1 > soundwire sdw:0:0217:f001:00:0: Runtime PM usage count underflow! > > Fixes: 57ed510b0547 ("soundwire: qcom: use pm_runtime_resume_and_get()") > Signed-off-by: Krzysztof Kozlowski Yes, this resume_and_get() added more problems indeed. One of those well-intended changes that went sideways. Reviewed-by: Pierre-Louis Bossart > --- > drivers/soundwire/qcom.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c > index aad5942e5980..f442280af9d3 100644 > --- a/drivers/soundwire/qcom.c > +++ b/drivers/soundwire/qcom.c > @@ -614,11 +614,12 @@ static irqreturn_t qcom_swrm_wake_irq_handler(int irq, void *dev_id) > struct qcom_swrm_ctrl *ctrl = dev_id; > int ret; > > - ret = pm_runtime_resume_and_get(ctrl->dev); > + ret = pm_runtime_get_sync(ctrl->dev); > if (ret < 0 && ret != -EACCES) { > dev_err_ratelimited(ctrl->dev, > - "pm_runtime_resume_and_get failed in %s, ret %d\n", > + "pm_runtime_get_sync failed in %s, ret %d\n", > __func__, ret); > + pm_runtime_put_noidle(ctrl->dev); > return ret; > } > > @@ -1197,11 +1198,12 @@ static int qcom_swrm_startup(struct snd_pcm_substream *substream, > struct snd_soc_dai *codec_dai; > int ret, i; > > - ret = pm_runtime_resume_and_get(ctrl->dev); > + ret = pm_runtime_get_sync(ctrl->dev); > if (ret < 0 && ret != -EACCES) { > dev_err_ratelimited(ctrl->dev, > - "pm_runtime_resume_and_get failed in %s, ret %d\n", > + "pm_runtime_get_sync failed in %s, ret %d\n", > __func__, ret); > + pm_runtime_put_noidle(ctrl->dev); > return ret; > } > > @@ -1402,11 +1404,12 @@ static int swrm_reg_show(struct seq_file *s_file, void *data) > struct qcom_swrm_ctrl *ctrl = s_file->private; > int reg, reg_val, ret; > > - ret = pm_runtime_resume_and_get(ctrl->dev); > + ret = pm_runtime_get_sync(ctrl->dev); > if (ret < 0 && ret != -EACCES) { > dev_err_ratelimited(ctrl->dev, > - "pm_runtime_resume_and_get failed in %s, ret %d\n", > + "pm_runtime_get_sync failed in %s, ret %d\n", > __func__, ret); > + pm_runtime_put_noidle(ctrl->dev); > return ret; > } >