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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D4EFC56201 for ; Wed, 25 Nov 2020 20:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C4CA2075A for ; Wed, 25 Nov 2020 20:50:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HoGgaYgz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730384AbgKYUub (ORCPT ); Wed, 25 Nov 2020 15:50:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:39650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729826AbgKYUua (ORCPT ); Wed, 25 Nov 2020 15:50:30 -0500 Received: from localhost (129.sub-72-107-112.myvzw.com [72.107.112.129]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3BABE206F9; Wed, 25 Nov 2020 20:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606337430; bh=5l1FeLkZJdwH1QPiZKXdyCL7G2w+EaBDfxGPhOyo+0s=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=HoGgaYgz1Ikf+/S41EjmERZvhGw+gImaPliYdSMlGcvzIfFSaePa8og9hhicv58pT 6Ks33/EwQ27IkqSYLNiBGBldEzbRaEghhGr2grzeDjCHjPobOZI2P9pTu1RPjvkG53 JlKL7mglLxLGK74Nou3cwFbvHi0u0ZEsk8al739Y= Date: Wed, 25 Nov 2020 14:50:28 -0600 From: Bjorn Helgaas To: Kuppuswamy Sathyanarayanan Cc: bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, knsathya@kernel.org Subject: Re: [PATCH v11 3/5] ACPI/PCI: Ignore _OSC DPC negotiation result if pcie_ports_dpc_native is set. Message-ID: <20201125205028.GA677519@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0ec11f2b7470070768886a138f2a755620725a06.1603766889.git.sathyanarayanan.kuppuswamy@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Oct 26, 2020 at 07:57:06PM -0700, Kuppuswamy Sathyanarayanan wrote: > pcie_ports_dpc_native is set only if user requests native handling > of PCIe DPC capability via pcie_port_setup command line option. > User input takes precedence over _OSC based control negotiation > result. So consider the _OSC negotiated result for DPC ownership > only if pcie_ports_dpc_native is unset. > > Signed-off-by: Kuppuswamy Sathyanarayanan > --- > drivers/acpi/pci_root.c | 8 ++++++-- > drivers/pci/pcie/dpc.c | 3 ++- > drivers/pci/pcie/portdrv.h | 2 -- > drivers/pci/pcie/portdrv_core.c | 2 +- > include/linux/pci.h | 2 ++ > 5 files changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index a9e6b782622d..2e2bc80c42fe 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -933,8 +933,12 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, > host_bridge->native_pme); > OSC_OWNER(ctrl, OSC_PCI_EXPRESS_LTR_CONTROL, > host_bridge->native_ltr); > - OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL, > - host_bridge->native_dpc); > + if (pcie_ports_dpc_native) > + dev_warn(&bus->dev, "OS forcibly taking over DPC\n"); > + else > + OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL, > + host_bridge->native_dpc); > + > } > > if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL)) > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c > index e05aba86a317..21f77420632b 100644 > --- a/drivers/pci/pcie/dpc.c > +++ b/drivers/pci/pcie/dpc.c > @@ -283,11 +283,12 @@ void pci_dpc_init(struct pci_dev *pdev) > static int dpc_probe(struct pcie_device *dev) > { > struct pci_dev *pdev = dev->port; > + struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus); > struct device *device = &dev->device; > int status; > u16 ctl, cap; > > - if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native) > + if (!pcie_aer_is_native(pdev) && !host->native_dpc) > return -ENOTSUPP; Wow, I don't even know what those negations mean and I don't want to take ten minutes to figure it out. Not your fault, obviously; it was that way before. "If AER is not native and DPC is not native, return -ENOTSUPP"? In other words, "if not (AER is native OR DPC is native), return -ENOTSUPP"? Or "if (AER is native OR DPC is native), keep going"? I guess this is tied up with 35a0b2378c19 ("PCI/DPC: Add "pcie_ports=dpc-native" to allow DPC without AER control") But we still ought to be able to consolidate some of this testing in acpi_pci_root_create() so we only have to look at host->native_dpc here (and maybe dev->aer_cap). > status = devm_request_threaded_irq(device, dev->irq, dpc_irq, > diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h > index af7cf237432a..0ac20feef24e 100644 > --- a/drivers/pci/pcie/portdrv.h > +++ b/drivers/pci/pcie/portdrv.h > @@ -25,8 +25,6 @@ > > #define PCIE_PORT_DEVICE_MAXSERVICES 5 > > -extern bool pcie_ports_dpc_native; > - > #ifdef CONFIG_PCIEAER > int pcie_aer_init(void); > int pcie_aer_is_native(struct pci_dev *dev); > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > index ccd5e0ce5605..2c0278f0fdcc 100644 > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -253,7 +253,7 @@ static int get_port_device_capability(struct pci_dev *dev) > */ > if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && > pci_aer_available() && > - (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER))) > + (host->native_dpc || (services & PCIE_PORT_SERVICE_AER))) > services |= PCIE_PORT_SERVICE_DPC; > > if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM || > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 22207a79762c..388121ec88b5 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1559,9 +1559,11 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d, > #ifdef CONFIG_PCIEPORTBUS > extern bool pcie_ports_disabled; > extern bool pcie_ports_native; > +extern bool pcie_ports_dpc_native; > #else > #define pcie_ports_disabled true > #define pcie_ports_native false > +#define pcie_ports_dpc_native false > #endif > > #define PCIE_LINK_STATE_L0S BIT(0) > -- > 2.17.1 >