From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E326E137E for ; Sat, 8 Feb 2025 18:51:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739040687; cv=none; b=JLI9wXCZhze9DXuhaX+lasy2HAnnSAuS8CoBGpfHazjwr0lEVaDClU6nFC9ezQjsTvUyeicpufnjDSYo1ayWZFaWXrch753SXi9Jm8DppqzYNHpEMVFEllptV9puxF8KBJ1+N29btZHrd/ebx44pPQSArj9WjzH5XI9zYLP/nRs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739040687; c=relaxed/simple; bh=ocQtBMyOozySwQUoJT5XoGfejv3UAKO+w7LOrRwBmi4=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=mtw8VgClvql9kLMI3Y6i0aFH1BzXZHiJKmyyyVEHqdPOHR5G1zB9ABfKnjcqjhu8drqVJCAPNZOLqVnjGBt9vagybs/tgTh9KIYJpwrAvCuqqpP0loNMERPT01l2GuOru8ylN1/8rTntxNJTyIO1slAeQ9BjbTvZku3JwewOG0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cSLxDSiN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cSLxDSiN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D750C4CED6; Sat, 8 Feb 2025 18:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739040686; bh=ocQtBMyOozySwQUoJT5XoGfejv3UAKO+w7LOrRwBmi4=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=cSLxDSiNI9z7JD5E3qbP2Q9bNIajFXQ8nkWOG0DQD+LvxmAybYhZY/We1rTFe5WN8 H/4gqZ2VlwqkDBFVwDD3gA5gAMnNLiLWx4EAULgyUmNoDIK6Ge9ISJxTFfS5ZhCwq9 aQnCXZxmxhxi0gL37uUSrJvwnqNAg62ZSNW2zIOesqeCSgH9mQSTiRqD/JzWTv9zvv m89R7lubffnQ5AgmW8dKkBUfl39ayKvX+wUlpNzRXw75uGBjwhPMci+6nDTgDShB/H C7OHSJCoix8XmXrpktZ9PU0yR9LuqbX6szaUwsLTaWYw+e8cjLbHDFxl83ys3IPY5v pn6U8As/qI7VQ== Date: Sat, 8 Feb 2025 12:51:24 -0600 From: Bjorn Helgaas To: Manivannan Sadhasivam Cc: kbusch@kernel.org, axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, andersson@kernel.org, konradybcio@kernel.org, rafael@kernel.org, ulf.hansson@linaro.org Subject: Re: [PATCH] nvme-pci: Use NVME_QUIRK_SIMPLE_SUSPEND for Qualcomm Snapdragon 8cx Gen 3 platforms Message-ID: <20250208185124.GA1120888@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250126050309.7243-1-manivannan.sadhasivam@linaro.org> On Sun, Jan 26, 2025 at 10:33:09AM +0530, Manivannan Sadhasivam wrote: > On these platforms, power to the PCIe bus is not retained if the SoC enters > its own deep low power state called, CX power collapse state during system > suspend. Once the SoC resumes after going through CX power collapse, all > the PCIe bus state will be lost. So the NVMe devices on these platforms > won't resume properly, rendering the machines useless until forcefully > restarted by the users. I guess "forcefully restarted" means a power cycle? > +++ b/drivers/nvme/host/pci.c > @@ -3162,6 +3162,16 @@ static unsigned long check_vendor_combination_bug(struct pci_dev *pdev) > if (dmi_match(DMI_BOARD_NAME, "LXKT-ZXEG-N6")) > return NVME_QUIRK_NO_APST; > > + /* > + * Qualcomm Snapdragon 8cx Gen 3 (SC8280XP) platforms doesn't retain > + * power to the PCIe bus after entering low power CX power collapse > + * state during system suspend. So shutdown the NVMe devices to have a > + * working system suspend on these platforms. > + */ > + if (dmi_match(DMI_PRODUCT_FAMILY, "SCP_MAKENA") || > + dmi_match(DMI_PRODUCT_FAMILY, "ThinkPad X13s Gen 1")) > + return NVME_QUIRK_SIMPLE_SUSPEND; I certainly acknowledge that this is a big problem for users. At the same time, this seems like a maintenance nightmare of platform-specific hacks scattered through endpoint drivers.