On 2021/8/5 7:29, Bjorn Helgaas wrote:

On Wed, Aug 04, 2021 at 09:47:04PM +0800, Dongdong Liu wrote:

quoted

Enable VF 10-Bit Tag Requester when it's upstream component support
10-bit Tag Completer.

s/it's/its/
s/support/supports/

Will fix.

I think "upstream component" here means the PF, doesn't it?  I don't
think the PF is really an *upstream* component; there's no routing
like with a switch.

I want to say the switch and root port devices that support 10-Bit
Tag Completer. Sure, VF also needs to have 10-bit Tag Requester
Supported capability.

quoted

Signed-off-by: Dongdong Liu <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/pci/iov.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index dafdc65..0d0bed1 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c

@@ -634,6 +634,10 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)

 	pci_iov_set_numvfs(dev, nr_virtfn);
 	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
+	if ((iov->cap & PCI_SRIOV_CAP_VF_10BIT_TAG_REQ) &&
+	    dev->ext_10bit_tag)
+		iov->ctrl |= PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN;
+
 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	msleep(100);

@@ -650,6 +654,8 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)

 err_pcibios:
 	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+	if (iov->ctrl & PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN)
+		iov->ctrl &= ~PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN;
 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	ssleep(1);

@@ -682,6 +688,8 @@ static void sriov_disable(struct pci_dev *dev)

 	sriov_del_vfs(dev);
 	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+	if (iov->ctrl & PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN)
+		iov->ctrl &= ~PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN;

You can just clear PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN unconditionally,
can't you?  I know it wouldn't change anything, but removing the "if"
makes the code prettier.  You could just add it in the existing
PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE mask.

Will do.

Thanks,
Dongdong

quoted

 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	ssleep(1);
--
2.7.4

.