VF BARs are read-only zeroes according to SRIOV spec,
the normal way(writing BARs) of allocating resources wouldn't
be applied to VFs. The VFs' resources would be allocated
when we enable SR-IOV capability. So we should not try to
reassign alignment after we enable VFs. It's meaningless
and will release the allocated resources which leads to a bug.
Signed-off-by: Yongji Xie <xyj...@linux.vnet.ibm.com>
---
drivers/pci/pci.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2d85a96..b8357d7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5048,6 +5048,15 @@ void pci_reassigndev_resource_alignment(struct pci_dev
*dev)
resource_size_t align, size;
u16 command;
+ /*
+ * VF BARs are RO zero according to SR-IOV spec 3.4.1.11. Their
+ * resources would be allocated when we enable them and not be
+ * re-allocated any more. So we should never try to reassign
+ * VF's alignment here.
+ */
+ if (dev->is_virtfn)
+ return;
+
/* check if specified PCI is target device to reassign */
align = pci_specified_resource_alignment(dev);
if (!align)
--
1.7.9.5
