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 73828C433F5 for ; Fri, 3 Dec 2021 14:00:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381310AbhLCOED (ORCPT ); Fri, 3 Dec 2021 09:04:03 -0500 Received: from mail-oi1-f173.google.com ([209.85.167.173]:44729 "EHLO mail-oi1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352843AbhLCOEC (ORCPT ); Fri, 3 Dec 2021 09:04:02 -0500 Received: by mail-oi1-f173.google.com with SMTP id be32so5911496oib.11; Fri, 03 Dec 2021 06:00:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=jqRgFTDUNv+vk88WWxS+gLyfj0EmvwrZNO1+l4H+s28=; b=xFFVK+AwaRAwx0mVsO7+qitJHMPOYBdgFbH/KEfsSRUHJGf23R0BtV8z2/jiz/yelV Vn9ueimuhgmlyqL8HkMGA3oOeZSt5YwmJJizE2pG58GzW/qmg9js0vXsyA1eZppVvsBt D5+jyZOdtkMs1r5APFW4A+maBAjmrBxR/7ER4qMYQZQYqVNiuNp99nJqU9GGWH6w/qny cA97jAwwqoCh57919Gd7ovqn+zD2V32HugpkmuRrTNYZo15jZbpbot/1S3eSVXCclXPK zxI4/dJgvANCTTOiXq3tp0B25V204HTyrVIIpnHAtxuUUSXoTg/L10bRhRhvJHYv2EF3 LVrw== X-Gm-Message-State: AOAM531vhxnGw+1Nb9RNGU9Nip7Pmxta3PLLHZSodzM/UcYkg6V+nnwB y6BwKFdcUlYzwkGyuNEP1475aAORRI0YB/Y0LXs= X-Google-Smtp-Source: ABdhPJyPrO3jM6MZMOz7vxO0EJn/Cia/2T6cQ8bgT83DHbGR/GRB4cWEnuf82PvmzLDs3OeZr9pvRtA3OCUxKCNRqWE= X-Received: by 2002:a05:6808:14c2:: with SMTP id f2mr9914172oiw.154.1638540037639; Fri, 03 Dec 2021 06:00:37 -0800 (PST) MIME-Version: 1.0 References: <20211203031541.1428904-1-kai.heng.feng@canonical.com> In-Reply-To: <20211203031541.1428904-1-kai.heng.feng@canonical.com> From: "Rafael J. Wysocki" Date: Fri, 3 Dec 2021 15:00:25 +0100 Message-ID: Subject: Re: [PATCH v3] PCI: vmd: Honor ACPI _OSC on PCIe features To: Kai-Heng Feng Cc: Bjorn Helgaas , Linux PM , "Rafael J . Wysocki" , Nirmal Patel , Jonathan Derrick , Lorenzo Pieralisi , Rob Herring , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Linux PCI , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 3, 2021 at 4:16 AM Kai-Heng Feng wrote: > > When Samsung PCIe Gen4 NVMe is connected to Intel ADL VMD, the > combination causes AER message flood and drags the system performance > down. > > The issue doesn't happen when VMD mode is disabled in BIOS, since AER > isn't enabled by acpi_pci_root_create() . When VMD mode is enabled, AER > is enabled regardless of _OSC: > [ 0.410076] acpi PNP0A08:00: _OSC: platform does not support [AER] > ... > [ 1.486704] pcieport 10000:e0:06.0: AER: enabled with IRQ 146 > > Since VMD is an aperture to regular PCIe root ports, honor ACPI _OSC to > disable PCIe features accordingly to resolve the issue. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215027 > Suggested-by: Rafael J. Wysocki > Signed-off-by: Kai-Heng Feng > --- > v3: > - Use a new helper function. > > v2: > - Use pci_find_host_bridge() instead of open coding. > > drivers/pci/controller/vmd.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index a45e8e59d3d48..691765e6c12aa 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -661,6 +661,21 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) > return 0; > } > > +/* > + * Since VMD is an aperture to regular PCIe root ports, only allow it to > + * control features that the OS is allowed to control on the physical PCI bus. > + */ I'd put the comment inside the function, but nevertheless Reviewed-by: Rafael J. Wysocki > +static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge, > + struct pci_host_bridge *vmd_bridge) > +{ > + vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug; > + vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug; > + vmd_bridge->native_aer = root_bridge->native_aer; > + vmd_bridge->native_pme = root_bridge->native_pme; > + vmd_bridge->native_ltr = root_bridge->native_ltr; > + vmd_bridge->native_dpc = root_bridge->native_dpc; > +} > + > static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) > { > struct pci_sysdata *sd = &vmd->sysdata; > @@ -798,6 +813,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) > return -ENODEV; > } > > + vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus), > + to_pci_host_bridge(vmd->bus->bridge)); > + > vmd_attach_resources(vmd); > if (vmd->irq_domain) > dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain); > -- > 2.32.0 >