From ff45f9ddbcf5418ff6402432d14ad91a40d9bea9 Mon Sep 17 00:00:00 2001 From: Ben Shelton Date: Thu, 29 Oct 2015 16:20:31 -0500 Subject: [PATCH] PCI: Enable SR-IOV ARI Capable Hierarchy before reading TotalVFs For some SR-IOV devices, the number of available virtual functions, i.e., TotalVFs, increases after setting the ARI Capable Hierarchy bit in the SR-IOV Control register. This violates the SR-IOV spec, r1.1, sec 3.3.6, which says TotalVFs is HwInit, but we don't need TotalVFs before setting the ARI Capable bit anyway. Set the ARI Capable Hierarchy bit (if ARI is enabled in the upstream bridge) before reading TotalVFs. [bhelgaas: changelog] Signed-off-by: Ben Shelton Signed-off-by: Bjorn Helgaas --- drivers/pci/iov.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee0ebff103a4..0cdb2d1e1a20 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) @@ -420,6 +416,10 @@ found: if (!offset || (total > 1 && !stride)) return -EIO; + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); + if (!total) + return 0; + pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz); i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0; pgsz &= ~((1 << i) - 1); -- 2.39.5