On 7/3/2025 8:39 PM, Vivek.Pernamitta@xxxxxxxxxxx wrote:
From: Vivek Pernamitta <quic_vpernami@xxxxxxxxxxx>
In SRIOV enabled devices, the VF DEVICE/VENDOR ID register returns FFFFh
when read (PCIe SRIOV spec-3.4.1.1). Therefore, read the PCIe
SUBSYSTEM_VENDOR_ID to check if the device is active.
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
- Krishna Chaitanya.
Signed-off-by: Vivek Pernamitta <quic_vpernami@xxxxxxxxxxx>
---
drivers/bus/mhi/host/pci_generic.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 22de02c26ceb946fb618d962ac8882d2db1be6b4..938f37d306a18b9a47f302df85697f837c225f0d 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -1025,8 +1025,10 @@ static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
u16 vendor = 0;
- if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
- return false;
+ if (pdev->is_virtfn)
+ pci_read_config_word(pdev, PCI_SUBSYSTEM_VENDOR_ID, &vendor);
+ else
+ pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor);
if (vendor == (u16) ~0 || vendor == 0)
return false;
