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>
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index aa77538..7a451ff 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3081,10 +3081,36 @@
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;