For some SR-IOV devices, the number of available virtual functions increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved off before the ARI control bit is enabled in SRIOV_CTRL. This causes an issue when VFs are enabled. At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain the number of available VFs for the device. sriov_enable() does a sanity check that SRIOV_INITIAL_VF is not greater than iov->total_VFs, the saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, and the VFs cannot be enabled. To fix the issue, write SRIOV_CTRL first, and then read SRIOV_NUM_VF. Signed-off-by: Ben Shelton <benjamin.h.shelton@xxxxxxxxx> --- Changes since v1: * Moved read of SRIOV_NUM_VF rather than re-reading it if ARI was enabled. drivers/pci/iov.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee0ebff..0174044 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -399,10 +399,6 @@ static int sriov_init(struct pci_dev *dev, int pos) ssleep(1); } - pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); - if (!total) - return 0; - ctrl = 0; list_for_each_entry(pdev, &dev->bus->devices, bus_list) if (pdev->is_physfn) @@ -414,6 +410,11 @@ static int sriov_init(struct pci_dev *dev, int pos) found: pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); + + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); + if (!total) + return 0; + pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset); pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride); -- 1.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
