From f65fd1aa4f9881d5540192d11f7b8ed2fec936db Mon Sep 17 00:00:00 2001 From: Sasha Neftin Date: Mon, 3 Apr 2017 16:02:50 -0500 Subject: [PATCH] PCI: Avoid FLR for Intel 82579 NICs Per Intel Specification Update 335553-002 (see link below), some 82579 network adapters advertise a Function Level Reset (FLR) capability, but they can hang when an FLR is triggered. To reproduce the problem, attach the device to a VM, then detach and try to attach again. Add a quirk to prevent the use of FLR on these devices. [bhelgaas: changelog, comments] Link: http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/82579lm-82579v-gigabit-network-connection-spec-update.pdf Signed-off-by: Sasha Neftin Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 6 ++++++ drivers/pci/quirks.c | 8 ++++++++ include/linux/pci.h | 2 ++ 3 files changed, 16 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 f754453fe754..823271b13d12 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4633,3 +4633,11 @@ 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); + +/* FLR may cause some 82579 devices to hang. */ +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 eb3da1a04e6c..22cad2c66d59 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 << 10), }; enum pci_irq_reroute_variant { -- 2.39.5