From 76b57c6700e56d146938ca9dc1d553557e940d9f Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Wed, 22 Aug 2012 09:41:27 -0600 Subject: 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 --- drivers/pci/quirks.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index aa77538c50c7..7a451ff56ecc 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -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; -- cgit v1.2.3