From patchwork Mon Nov 21 18:16:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 13051523 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 BE6F4C4332F for ; Mon, 21 Nov 2022 18:18:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229687AbiKUSS0 (ORCPT ); Mon, 21 Nov 2022 13:18:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbiKUSSZ (ORCPT ); Mon, 21 Nov 2022 13:18:25 -0500 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B5E2C6BE0; Mon, 21 Nov 2022 10:18:23 -0800 (PST) Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 5.1.0) id 8955e2bb27aa72ee; Mon, 21 Nov 2022 19:18:19 +0100 Received: from kreacher.localnet (unknown [213.134.163.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by v370.home.net.pl (Postfix) with ESMTPSA id 1D520780F76; Mon, 21 Nov 2022 19:18:19 +0100 (CET) Authentication-Results: v370.home.net.pl; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: v370.home.net.pl; spf=fail smtp.mailfrom=rjwysocki.net From: "Rafael J. Wysocki" To: Bjorn Helgaas Cc: Rodrigo Vivi , Lukas Wunner , LKML , Linux ACPI , Linux PCI , Linux PM , Mika Westerberg Subject: [PATCH v1 2/2] ACPI: PCI: hotplug: Avoid setting is_hotplug_bridge for PCIe Upstream Ports Date: Mon, 21 Nov 2022 19:16:57 +0100 Message-ID: <2262230.ElGaqSPkdT@kreacher> In-Reply-To: <5623410.DvuYhMxLoT@kreacher> References: <5623410.DvuYhMxLoT@kreacher> MIME-Version: 1.0 X-CLIENT-IP: 213.134.163.140 X-CLIENT-HOSTNAME: 213.134.163.140 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvgedrheeigdduudduucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppedvudefrddufeegrdduieefrddugedtnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvddufedrudefgedrudeifedrudegtddphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohepkedprhgtphhtthhopehhvghlghgrrghssehkvghrnhgvlhdrohhrghdprhgtphhtthhopehrohgurhhighhordhvihhvihesihhnthgvlhdrtghomhdprhgtphhtthhopehluhhkrghsseifuhhnnhgvrhdruggvpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqrggtphhisehv ghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqphgtihesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehmihhkrgdrfigvshhtvghrsggvrhhgsehlihhnuhigrdhinhhtvghlrdgtohhm X-DCC--Metrics: v370.home.net.pl 1024; Body=8 Fuz1=8 Fuz2=8 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Rafael J. Wysocki It is reported that on some systems pciehp binds to an Upstream Port and attempts to operate it which causes devices below the Port to disappear from the bus. This happens because acpiphp sets is_hotplug_bridge for that Port (after receiving a Device Check notification on it from the platform firmware via ACPI) during the enumeration of PCI devices and so when get_port_device_capability() runs, it sees that is_hotplug_bridge is set and adds PCIE_PORT_SERVICE_HP to Port services (which allows pciehp to bind to the Port in question). Even though this particular problem can be addressed by making the portdrv_core checks more robust, it also causes power management to work differently on the affected systems which generally is not desirable (PCIe Ports with is_hotplug_bridge set have to pass additional tests to be allowed to go into the D3hot/cold power states which affects runtime PM of devices below these Ports). For this reason, amend check_hotplug_bridge() with a PCIe type check to prevent it from setting is_hotplug_bridge for Upstream Ports. Reported-by: Rodrigo Vivi Suggested-by: Lukas Wunner Signed-off-by: Rafael J. Wysocki Tested-by: Rodrigo Vivi Reviewed-by: Rodrigo Vivi --- drivers/pci/hotplug/acpiphp_glue.c | 8 ++++++++ 1 file changed, 8 insertions(+) Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -411,6 +411,14 @@ static void check_hotplug_bridge(struct if (dev->is_hotplug_bridge) return; + /* + * In the PCIe case, only Root Ports and Downstream Ports are capable of + * accommodating hotplug devices, so avoid marking Upstream Ports as + * "hotplug bridges". + */ + if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) + return; + list_for_each_entry(func, &slot->funcs, sibling) { if (PCI_FUNC(dev->devfn) == func->function) { dev->is_hotplug_bridge = 1;