Wei,
On 2015/10/30 13:14, Wei Yang wrote:
On Thu, Oct 29, 2015 at 05:23:22PM -0500, Bjorn Helgaas wrote:
From: Alexander Duyck <aduyck@xxxxxxxxxxxx>
Per sec 3.3.3.1 of the SR-IOV spec, r1.1, we must allow 1.0s after clearing
VF Enable before reading any field in the SR-IOV Extended Capability.
Wait 1 second before calling pci_iov_set_numvfs(), which reads
PCI_SRIOV_VF_OFFSET and PCI_SRIOV_VF_STRIDE after it sets PCI_SRIOV_NUM_VF.
[bhelgaas: split to separate patch for reviewability, add spec reference]
Signed-off-by: Alexander Duyck <aduyck@xxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/iov.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index fada98d..24428d5 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -339,13 +339,13 @@ failed:
iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
pci_cfg_access_lock(dev);
pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
- pci_iov_set_numvfs(dev, 0);
ssleep(1);
pci_cfg_access_unlock(dev);
if (iov->link != dev->devfn)
sysfs_remove_link(&dev->dev.kobj, "dep_link");
+ pci_iov_set_numvfs(dev, 0);
One small question, any specific reason put it here instead of just after
sleep()?
Agree, pci_iov_set_numvfs(dev, 0) should be put before
pci_cfg_access_unlock(dev) to avoid race, because "NumVFs may only be
written while VF Enable is Clear"
Thanks,
Ethan
return rc;
}
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