From mboxrd@z Thu Jan 1 00:00:00 1970 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 2E0EFC74A4B for ; Fri, 10 Mar 2023 15:15:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233995AbjCJPP1 (ORCPT ); Fri, 10 Mar 2023 10:15:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234119AbjCJPOy (ORCPT ); Fri, 10 Mar 2023 10:14:54 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0061D22A36 for ; Fri, 10 Mar 2023 07:06:14 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id ABBDE61A2D for ; Fri, 10 Mar 2023 15:04:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9266C433EF; Fri, 10 Mar 2023 15:04:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678460689; bh=KclkMe7vaJVc5/+HJPw2cV9wB6hnn3zz8dKfRHN8ok4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wKTzwy9aFydX5XtZxBETKRRyhOVBI3STJfGSIGbGGBV3+U5vVq+wDVnqE1AnCgiwS b3RrKsvbyFbBMxVRPWTqUYcEdCqNULuKYdHJQbo8vRDnp37lkPrARD97VshqjFjL/X xS8SHYQzHBHES7wiZAmjctGzdWCgoPE4r/6GNbgA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ravi Kishore Koppuravuri , Lukas Wunner , Bjorn Helgaas , Mika Westerberg , Kuppuswamy Sathyanarayanan Subject: [PATCH 5.10 419/529] PCI/PM: Observe reset delay irrespective of bridge_d3 Date: Fri, 10 Mar 2023 14:39:22 +0100 Message-Id: <20230310133824.405130904@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133804.978589368@linuxfoundation.org> References: <20230310133804.978589368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lukas Wunner commit 8ef0217227b42e2c34a18de316cee3da16c9bf1e upstream. If a PCI bridge is suspended to D3cold upon entering system sleep, resuming it entails a Fundamental Reset per PCIe r6.0 sec 5.8. The delay prescribed after a Fundamental Reset in PCIe r6.0 sec 6.6.1 is sought to be observed by: pci_pm_resume_noirq() pci_pm_bridge_power_up_actions() pci_bridge_wait_for_secondary_bus() However, pci_bridge_wait_for_secondary_bus() bails out if the bridge_d3 flag is not set. That flag indicates whether a bridge is allowed to suspend to D3cold at *runtime*. Hence *no* delay is observed on resume from system sleep if runtime D3cold is forbidden. That doesn't make any sense, so drop the bridge_d3 check from pci_bridge_wait_for_secondary_bus(). The purpose of the bridge_d3 check was probably to avoid delays if a bridge remained in D0 during suspend. However the sole caller of pci_bridge_wait_for_secondary_bus(), pci_pm_bridge_power_up_actions(), is only invoked if the previous power state was D3cold. Hence the additional bridge_d3 check seems superfluous. Fixes: ad9001f2f411 ("PCI/PM: Add missing link delays required by the PCIe spec") Link: https://lore.kernel.org/r/eb37fa345285ec8bacabbf06b020b803f77bdd3d.1673769517.git.lukas@wunner.de Tested-by: Ravi Kishore Koppuravuri Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg Reviewed-by: Kuppuswamy Sathyanarayanan Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4808,7 +4808,7 @@ void pci_bridge_wait_for_secondary_bus(s if (pci_dev_is_disconnected(dev)) return; - if (!pci_is_bridge(dev) || !dev->bridge_d3) + if (!pci_is_bridge(dev)) return; down_read(&pci_bus_sem);