From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout1.hostsharing.net (mailout1.hostsharing.net [83.223.95.204]) (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 2FF8C306D2A; Wed, 2 Sep 2026 18:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.204 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788375223; cv=none; b=M0Ucfjno4kX123eHvp571tle33flYPOKgdkCZSrfgMUQnV+NQBqjcBS89QXpjN+oX68r4Y5FkZmmeBfuiBY625ByqC2FbNb99vxTmyTMm02EETCWLSBXTGX1B5Uch7IUad81P3QQLNHz+UAlK3Wrl+0tYSNIUgALSWUddpmiyho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788375223; c=relaxed/simple; bh=aQ/e5iEi1Anvk7orns8m9DQiCpzgWQJgkqWEYMmEh5E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qVgokTlziTksyCRVV+y1WZkotbExZZoiqC++3bih0wqzhnV/k+ilzSi3QDNxl00hv9ive1RJWLe8FwAmvIxbMDU/udcYJQONX031V4+Wl+5I5FmA4lFa6RQ+B2IilsidKbtMVd3wVGTJa+QzYpevq5MAXoPBBr5NR4T8KKny+wQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=pass smtp.mailfrom=wunner.de; arc=none smtp.client-ip=83.223.95.204 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wunner.de Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384 client-signature ECDSA (secp384r1) client-digest SHA384) (Client CN "*.hostsharing.net", Issuer "GlobalSign GCC R6 AlphaSSL CA 2025" (verified OK)) by mailout1.hostsharing.net (Postfix) with ESMTPS id A3482148E; Wed, 02 Sep 2026 20:53:30 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 5E99F60DBD6D; Wed, 2 Sep 2026 20:53:30 +0200 (CEST) Date: Wed, 2 Sep 2026 20:53:30 +0200 From: Lukas Wunner To: Konrad Dybcio Cc: Bjorn Helgaas , Manivannan Sadhasivam , Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, mani@kernel.org Subject: Re: [PATCH v2] PCI: Allow D3 for native Hotplug capable Root Ports on non-x86 platforms Message-ID: References: <20260811232245.GA805297@bhelgaas> <3eeb3465-a1e6-4fdc-8019-3907d9c55691@gmail.com> 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: <3eeb3465-a1e6-4fdc-8019-3907d9c55691@gmail.com> On Wed, Sep 02, 2026 at 07:09:58PM +0200, Konrad Dybcio wrote: > > On Wed, Jul 29, 2026 at 06:50:05PM +0200, Manivannan Sadhasivam wrote: > >> Commit eb3b5bf1a88d ("PCI: Whitelist native hotplug ports for runtime D3"), > >> prevented native Hotplug capable Root Ports from entering D3 citing issues > >> on old Intel SkyLake Xeon-SP platform. > >> > >> But there is no reason to restrict D3 for native Hotplug capable Root > >> Ports on non-x86 platforms. We recently enabled D3 on non-Hotplug capable > >> Root Ports on non-x86 platforms (specifically for DT platforms) in commit > >> a5fb3ff63287 ("PCI: Allow PCI bridges to go to D3Hot on all non-x86"). So > >> do the same for native Hotplug capable Root Ports as well. > > This breaks system suspend entry (crashes the system) on Qualcomm SC8280XP > CRD.. this SoC is known for fragile PCIe. > > It doesn't repro on e.g. the Qualcomm Glymur CRD (2 gens newer), perhaps we > need an explicit opt-out like > > if (of_machine_is_compatible("qcom,sc8280xp")) > > or some targetted fix inside the qcom driver That's precisely the reason why x86 uses a BIOS cut-off date of 2015 in pci_bridge_d3_possible(): Root Ports on older SoCs were never validated for D3hot and are known to cause crashes etc when low power states are used. Thanks, Lukas