Commit 76b57c67 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI: Wait for pending transactions to complete before 82599 FLR 



Before initiating an FLR, we should wait for completion of any outstanding
non-posted requests.  See PCIe spec r3.0, sec 6.6.2.

This makes reset_intel_82599_sfp_virtfn() very similar to the generic
pcie_flr().  The only difference is that the 82599 doesn't report FLR
support in the VF Device Capability register.

Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 59875ae4

drivers/pci/quirks.c

+27 −1
Original line number Diff line number Diff line
@@ -3081,10 +3081,36 @@ static int reset_intel_generic_dev(struct pci_dev *dev, int probe) 


static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)

{

	int i;

	u16 status;



	/*

	 * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf

	 *

	 * The 82599 supports FLR on VFs, but FLR support is reported only

	 * in the PF DEVCAP (sec 9.3.10.4), not in the VF DEVCAP (sec 9.5).

	 * Therefore, we can't use pcie_flr(), which checks the VF DEVCAP.

	 */



	if (probe)

		return 0;



	pcie_capability_write_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);

	/* Wait for Transaction Pending bit clean */

	for (i = 0; i < 4; i++) {

		if (i)

			msleep((1 << (i - 1)) * 100);



		pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &status);

		if (!(status & PCI_EXP_DEVSTA_TRPND))

			goto clear;

	}



	dev_err(&dev->dev, "transaction is not cleared; "

			"proceeding with reset anyway\n");



clear:

	pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);



	msleep(100);



	return 0;

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