Commit f65fd1aa authored by Sasha Neftin's avatar Sasha Neftin Committed by Bjorn Helgaas
Browse files

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: default avatarSasha Neftin <sasha.neftin@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent c1ae3cfa

drivers/pci/pci.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

drivers/pci/quirks.c

+8 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -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 {

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