From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C923478276 for ; Thu, 18 Jul 2024 10:09:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.235.227.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721297379; cv=none; b=gbX9XTqlb5hddcDv6ejamIVOsxYmaIr3mGka3/P7hmz3KeG8mSpn/UGX9X7LN7AFnSbfXKZuvN/R3yGi9U0Un/iVovcwENjwnu/mmpIhP/bgE6zZN9Pt6xwucxLaLPGYdNhDv0+jSc03asY30KCbyuzXj88spHZYDuORTv5d4Bw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721297379; c=relaxed/simple; bh=7W9NB+4beenTAyhTygX8/3CLonvIgT2Ws7zp0jH0pWk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Xb7ie4tgX6SB9e0ITG1invCnILIKJuQZY4QXUpBq9ApH8uzfHBNtPyxWr1FHJlPIrYEahm+q/c7Bh3nTdBN/5JyZjjM5fmsTe+EIyf7eGCcmITGh+Np/51Mx9fBBWDYUyqL3ovHAsJ2392W1jsGfdKoQjdPWDgMnVlDzQ7pJWog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=oYggl5Yq; arc=none smtp.client-ip=46.235.227.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="oYggl5Yq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1721297373; bh=7W9NB+4beenTAyhTygX8/3CLonvIgT2Ws7zp0jH0pWk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=oYggl5YqOJlMmwn2fZXbxfLjSz9+mDZzx2Yu564ULzbOMeLZuLsGTkR2oOlw01KyW fBWieElXAsPOf3lqOQmpFxWNMf5SR16lha+HGu5cZP0bAiM1OZpkrt1yWdgqIdQJ6o s7Ckc5/xpPpKXd5Xh3Jeo8W6mSPa2ME22AWqgENFSE3s/tdG0TB9Y/B3ltHyEUsttN JX/vHpHmI5peAgzgAicMmD4Gchp7uTphNywZh/iezEKGgX4CmXrcGb3js53NF/sl53 VOOFuCgCATbK5IbcoRAMbDohrGLqA6zkfj0gbQxZhEXI8wnMTEbLSUCxWsU1N9ZQtv /IIQJ7nPXaMkw== Received: from [100.113.186.2] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madrid.collaboradmins.com (Postfix) with ESMTPSA id B1F99378020A; Thu, 18 Jul 2024 10:09:32 +0000 (UTC) Message-ID: <8fbe44af-8da3-4554-ac2b-5db58003449e@collabora.com> Date: Thu, 18 Jul 2024 12:09:31 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mailbox: mtk-cmdq: Move devm_mbox_controller_register() after devm_pm_runtime_enable() To: jason-jh.lin@mediatek.com, Jassi Brar , CK Hu Cc: Jassi Brar , Matthias Brugger , Singo Chang , Nancy Lin , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Project_Global_Chrome_Upstream_Group@mediatek.com References: <20240718-mtk-cmdq-fixup-v2-1-f6bb3c052a60@mediatek.com> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20240718-mtk-cmdq-fixup-v2-1-f6bb3c052a60@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Il 18/07/24 10:38, Jason-JH.Lin via B4 Relay ha scritto: > From: "Jason-JH.Lin" > > When mtk-cmdq unbinds, a WARN_ON message with condition > pm_runtime_get_sync() < 0 occurs. > > According to the call tracei below: > cmdq_mbox_shutdown > mbox_free_channel > mbox_controller_unregister > __devm_mbox_controller_unregister > ... > > The root cause can be deduced to be calling pm_runtime_get_sync() after > calling pm_runtime_disable() as observed below: > 1. CMDQ driver uses devm_mbox_controller_register() in cmdq_probe() > to bind the cmdq device to the mbox_controller, so > devm_mbox_controller_unregister() will automatically unregister > the device bound to the mailbox controller when the device-managed > resource is removed. That means devm_mbox_controller_unregister() > and cmdq_mbox_shoutdown() will be called after cmdq_remove(). > 2. CMDQ driver also uses devm_pm_runtime_enable() in cmdq_probe() after > devm_mbox_controller_register(), so that devm_pm_runtime_disable() > will be called after cmdq_remove(), but before > devm_mbox_controller_unregister(). > > To fix this problem, cmdq_probe() needs to move > devm_mbox_controller_register() after devm_pm_runtime_enable() to make > devm_pm_runtime_disable() be called after > devm_mbox_controller_unregister(). > > Fixes: 623a6143a845 ("mailbox: mediatek: Add Mediatek CMDQ driver") > Signed-off-by: Jason-JH.Lin > --- > When mtk-cmdq unbinds, a WARN_ON message with condition > pm_runtime_get_sync() < 0 occurs. > > According to the call tracei below: > cmdq_mbox_shutdown > mbox_free_channel > mbox_controller_unregister > __devm_mbox_controller_unregister > ... > > The root cause can be deduced to be calling pm_runtime_get_sync() after > calling pm_runtime_disable() as observed below: > 1. CMDQ driver uses devm_mbox_controller_register() in cmdq_probe() > to bind the cmdq device to the mbox_controller, so > devm_mbox_controller_unregister() will automatically unregister > the device bound to the mailbox controller when the device-managed > resource is removed. That means devm_mbox_controller_unregister() > and cmdq_mbox_shoutdown() will be called after cmdq_remove(). > 2. CMDQ driver also uses devm_pm_runtime_enable() in cmdq_probe() after > devm_mbox_controller_register(), so that devm_pm_runtime_disable() > will be called after cmdq_remove(), but before > devm_mbox_controller_unregister(). > > To fix this problem, cmdq_probe() needs to move > devm_mbox_controller_register() after devm_pm_runtime_enable() to make > devm_pm_runtime_disable() be called after > devm_mbox_controller_unregister(). > > Change-Id: I4f0e68eac5186fe8041ea2f16c8e852d52d71cb0 > --- > Changes in v2: > - Change to move the calling sequence of devm_mbox_controller_register() > and devm_pm_runtime_enable(). > - Link to v1: https://lore.kernel.org/r/20240613150626.25280-1-jason-jh.lin@mediatek.com > --- > drivers/mailbox/mtk-cmdq-mailbox.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c > index f1dfce9e27f5..002003c3970a 100644 > --- a/drivers/mailbox/mtk-cmdq-mailbox.c > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c > @@ -370,6 +370,8 @@ static void cmdq_remove(struct platform_device *pdev) > { > struct cmdq *cmdq = platform_get_drvdata(pdev); > > + devm_mbox_controller_unregister(&pdev->dev, &cmdq->mbox); ...if you moved devm_mbox_controller_register() after devm_pm_runtime_enable(), this means that the teardown sequence will disable pm runtime after unregistering the mbox controller, so why do you need to call devm_mbox_controller_unregister() manually here? Cheers, Angelo > + > if (cmdq->pdata->sw_ddr_en) > cmdq_sw_ddr_enable(cmdq, false); > > @@ -689,12 +691,6 @@ static int cmdq_probe(struct platform_device *pdev) > cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i]; > } > > - err = devm_mbox_controller_register(dev, &cmdq->mbox); > - if (err < 0) { > - dev_err(dev, "failed to register mailbox: %d\n", err); > - return err; > - } > - > platform_set_drvdata(pdev, cmdq); > > WARN_ON(clk_bulk_prepare(cmdq->pdata->gce_num, cmdq->clocks)); > @@ -722,6 +718,12 @@ static int cmdq_probe(struct platform_device *pdev) > pm_runtime_set_autosuspend_delay(dev, CMDQ_MBOX_AUTOSUSPEND_DELAY_MS); > pm_runtime_use_autosuspend(dev); > > + err = devm_mbox_controller_register(dev, &cmdq->mbox); > + if (err < 0) { > + dev_err(dev, "failed to register mailbox: %d\n", err); > + return err; > + } > + > return 0; > } > > > --- > base-commit: 797012914d2d031430268fe512af0ccd7d8e46ef > change-id: 20240718-mtk-cmdq-fixup-40379650e96b > > Best regards,