From patchwork Wed Aug 30 14:24:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Glauber X-Patchwork-Id: 807656 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xj77v2503z9s8J for ; Thu, 31 Aug 2017 00:25:15 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751728AbdH3OZN (ORCPT ); Wed, 30 Aug 2017 10:25:13 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:37842 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751683AbdH3OZK (ORCPT ); Wed, 30 Aug 2017 10:25:10 -0400 Received: by mail-wm0-f66.google.com with SMTP id x189so1968587wmg.4; Wed, 30 Aug 2017 07:25:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=qaphwBHb+zU3ev3NVN7TOSSreMynoGbonAUKptoAR3s=; b=Q7Be0V5YFJWooHnBIxRvMBFzu2pXzXwy4k2+z1z2SNpOwLQAPBlXRvlyn9EIaaSD7W h/KU52f3HyMY8mxvBG3D9Tp0wJSkJFP4c/nK47Ajhkx7TMwAY7/yaSvZnu+fqxPoyztR agOPDHlJLp5Wpi3FxnI6ijv+rnDTImr67yObbLHwW3B95g9uL12iIO5l+t6bLqF/3RiA ZF1MNZmNU0MQvY6kgahE/eLOtRsEWKAVV5C/s923N5ZB2ZywEEj3k3gUPLaIW8CiLlA/ pp2wy5J9zXmfts6hNbRP3W8J+dUNISUQbyfTHuXBYP6/PTbEKibyrYYrqO0jdrtpV1km NjAg== X-Gm-Message-State: AHYfb5i+Tr6wjyyZma0rfYdr7Fi2ioijGX2Zcr334IwAw2RtQYC7n/H/ 5U1vE2p7KpuOAw== X-Received: by 10.28.157.19 with SMTP id g19mr1312673wme.42.1504103109598; Wed, 30 Aug 2017 07:25:09 -0700 (PDT) Received: from hc.fritz.box (HSI-KBW-46-223-66-184.hsi.kabel-badenwuerttemberg.de. [46.223.66.184]) by smtp.gmail.com with ESMTPSA id p105sm97012wrc.64.2017.08.30.07.25.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 30 Aug 2017 07:25:09 -0700 (PDT) From: Jan Glauber To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Alex Williamson , linux-kernel@vger.kernel.org, david.daney@cavium.com, Jon Masters , Robert Richter , linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, Jan Glauber Subject: [PATCH v3 1/3] PCI: Allow PCI_DEV_FLAGS_NO_BUS_RESET to be used on bus device Date: Wed, 30 Aug 2017 16:24:52 +0200 Message-Id: <20170830142454.10971-2-jglauber@cavium.com> X-Mailer: git-send-email 2.9.0.rc0.21.g7777322 In-Reply-To: <20170830142454.10971-1-jglauber@cavium.com> References: <20170830142454.10971-1-jglauber@cavium.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: David Daney When checking to see if a PCI bus can safely be reset, we check to see if any of the children have their PCI_DEV_FLAGS_NO_BUS_RESET flag set. As these devices are known not to behave well after a bus reset. Some PCIe root port bridges also do not behave well after a bus reset, sometimes causing the devices behind the bridge to become unusable. Add a check for the PCI_DEV_FLAGS_NO_BUS_RESET flag being set in the bridge device to allow these bridges to be flagged, and prevent their buses from being reset. A follow on patch will add a quirk for this type of bridge. Signed-off-by: David Daney [jglauber@cavium.com: fixed typo] Signed-off-by: Jan Glauber --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index af0cc34..d9abbc9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4290,6 +4290,10 @@ static bool pci_bus_resetable(struct pci_bus *bus) { struct pci_dev *dev; + + if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) + return false; + list_for_each_entry(dev, &bus->devices, bus_list) { if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || (dev->subordinate && !pci_bus_resetable(dev->subordinate)))