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: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Bjorn Helgaas 2012-08-22 09:41:27 -06:00
parent 59875ae489
commit 76b57c6700
1 changed files with 27 additions and 1 deletions

View File

@ -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;