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 6EA2F3933FC; Wed, 14 Jan 2026 16:45:40 +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=1768409140; cv=none; b=f9WLbIS5/jMuQbOsvIHU88sObt8EzEUv0JMx5IBncgwpPR6UVnvecOzLbfVn2HmBzP5gt71NnPeltA2PpDBc3F3ZLNgfAlNl0MNjhFxyUuD5qB6Z4BxeQykoa2zaqKTuTxhWSkowsU7SCrumTGirtiDBUw0PzBOMv/QqYWeT+GQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768409140; c=relaxed/simple; bh=ZtLzQt5YBwUg6DG6bIwSFawdoa7qArNKtK/7xD+zL0g=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=BSICV37OXpX/n9QyW9mhn9qkKzDYD0PAjj2Vb2v3nZ9sJs128KDks1DQtsHd5Tj+xzVEALwsEPrbFX2vSu+18+zv7rl/VRebt36uqfcShXnxpoopDvJzpFEHaByV8qgK+xe+u0rirkkX5EBBL3h+jJPR6v+8Gy8uoZ8ZJAqOckU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=azPrhNNp; 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="azPrhNNp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFBFAC4CEF7; Wed, 14 Jan 2026 16:45:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768409140; bh=ZtLzQt5YBwUg6DG6bIwSFawdoa7qArNKtK/7xD+zL0g=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=azPrhNNptoYR+pu6N29kqKJMY+m5eXR0VNujXN6qW/T0q/xFfmXR78t8jnqqjY7pr yXHAR+rFu/uNe+IlGnXvMRxPOtzi6fZyMoPA6XNCOe8gFbrKc7AE/AUZ5B7BZbH0uH XxrJFeM4z7rfyUjQlUr1az/F3xbBEdOMmKyx/MOcwxi15ZPbntzTbCdhzgIYA8vx8Y D6IakQxZznXplW0YVQRDbrpE+iCJnaHtuk/kfzVLC7Td9mI82IE4BlJYMhOdBKKAUD ZstS3mzdcVfzSAaLSE+33dWv7774z70++C/3nHyxefXaSQP0jOf5AiaUaNiB1a413p Vc3Qs83/4/ZyQ== Date: Wed, 14 Jan 2026 10:45:38 -0600 From: Bjorn Helgaas To: Marek Szyprowski Cc: Brian Norris , Bjorn Helgaas , Lukas Wunner , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J . Wysocki" , Ilpo =?utf-8?B?SsOkcnZpbmVu?= Subject: Re: [PATCH v4] PCI/PM: Prevent runtime suspend before devices are fully initialized Message-ID: <20260114164538.GA816227@bhelgaas> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0e35a4e1-894a-47c1-9528-fc5ffbafd9e2@samsung.com> On Wed, Jan 14, 2026 at 10:46:41AM +0100, Marek Szyprowski wrote: > On 06.01.2026 23:27, Bjorn Helgaas wrote: > > On Thu, Oct 23, 2025 at 02:09:01PM -0700, Brian Norris wrote: > >> Today, it's possible for a PCI device to be created and > >> runtime-suspended before it is fully initialized. When that happens, the > >> device will remain in D0, but the suspend process may save an > >> intermediate version of that device's state -- for example, without > >> appropriate BAR configuration. When the device later resumes, we'll > >> restore invalid PCI state and the device may not function. > ... > > Link: https://patch.msgid.link/20251023140901.v4.1.I60a53c170a8596661883bd2b4ef475155c7aa72b@changeid > > This patch landed recently in linux-next as commit c796513dc54e > ("PCI/PM: Prevent runtime suspend until devices are fully initialized"). > In my tests I found that it sometimes causes the "pci 0000:01:00.0: > runtime PM trying to activate child device 0000:01:00.0 but parent > (0000:00:00.0) is not active" warning on Qualcomm Robotics RB5 board > (arch/arm64/boot/dts/qcom/qrb5165-rb5.dts). This in turn causes a > lockdep warning about console lock, but this is just a consequence of > the runtime pm warning. Reverting $subject patch on top of current > linux-next hides this warning. I moved this patch from pci/pm to pci/pend to remove it from linux-next while we figure this out. Thanks for the report and debugging! Bjorn