From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:54358 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750945AbdDCVDY (ORCPT ); Mon, 3 Apr 2017 17:03:24 -0400 Date: Mon, 3 Apr 2017 16:03:19 -0500 From: Bjorn Helgaas To: Sasha Neftin Cc: linux-pci@vger.kernel.org, bhelgaas@google.com, alex.williamson@redhat.com, dima.ruinskiy@intel.com, alexander.h.duyck@intel.com Subject: Re: [PATCH] PCI: do not perform FLR for 82579 devices Message-ID: <20170403210319.GB13232@bhelgaas-glaptop.roam.corp.google.com> References: <20170319081542.20908-1-sasha.neftin@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170319081542.20908-1-sasha.neftin@intel.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Sun, Mar 19, 2017 at 10:15:42AM +0200, Sasha Neftin wrote: > This patch come to solve problem of 82579 network adapters hang. > Link on Datasheets and Specification Updates: > http://www.intel.com/content/www/us/en/embedded/products > /networking/82579-gigabit-ethernet-connection-family-documentation.html > Please, refer to Specification Update: > http://www.intel.com/content/dam/www/public/us/en/documents/ > specification-updates/ > 82579lm-82579v-gigabit-network-connection-spec-update.pdf > > Reproduction: > Attach the device to a VM, then detach and try to attach again. > > Fix: > Operating system won't support FLR for 82579 devices. > > Signed-off-by: Sasha Neftin Applied to pci/virtualization for v4.12, thanks! > --- > drivers/pci/pci.c | 6 ++++++ > drivers/pci/quirks.c | 13 +++++++++++++ > include/linux/pci.h | 2 ++ > 3 files changed, 21 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 7904d02ffdb9..bef14777bb30 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -3781,6 +3781,9 @@ static int pcie_flr(struct pci_dev *dev, int probe) > if (!(cap & PCI_EXP_DEVCAP_FLR)) > return -ENOTTY; > > + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) > + return -ENOTTY; > + > if (probe) > return 0; > > @@ -3801,6 +3804,9 @@ static int pci_af_flr(struct pci_dev *dev, int probe) > if (!pos) > return -ENOTTY; > > + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) > + return -ENOTTY; > + > pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap); > if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) > return -ENOTTY; > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 1800befa8b8b..eb333a61637e 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -4566,3 +4566,16 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2030, quirk_no_aersid); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2031, quirk_no_aersid); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2032, quirk_no_aersid); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2033, quirk_no_aersid); > + > +/* > + * Workaround FLR issues for 82579 devices > + * This code make sure not perform the FLR (Function Level Reset) via PCIe, > + * in order to workaround a bug found while using device passthrough, > + * where the interface would become non-responsive. > + */ > +static void quirk_intel_no_flr(struct pci_dev *dev) > +{ > + dev->dev_flags |= PCI_DEV_FLAGS_NO_FLR_RESET; > +} > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr); > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index e2d1a124216a..f4fea5ad2d12 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -178,6 +178,8 @@ enum pci_dev_flags { > PCI_DEV_FLAGS_NO_PM_RESET = (__force pci_dev_flags_t) (1 << 7), > /* Get VPD from function 0 VPD */ > PCI_DEV_FLAGS_VPD_REF_F0 = (__force pci_dev_flags_t) (1 << 8), > + /* Do not use FLR even if device advertises PCI_AF_CAP */ > + PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 9), > }; > > enum pci_irq_reroute_variant { > -- > 2.11.0 >