From: Hou Zhiqiang <zhiqiang....@nxp.com>
As the PCIe specification recommend reading the Vendor ID register
to determine if a Function is present, read the Vendor ID of a
non-existent Function must not result in system error, so we'd better
make the first CFG read to Vendor ID instead of Header Type register
in the PCIe enumeration.
Signed-off-by: Hou Zhiqiang <zhiqiang....@nxp.com>
---
drivers/pci/pci-uclass.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index eb118f3496..c8cb9cdad9 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -748,16 +748,19 @@ int pci_bind_bus_devices(struct udevice *bus)
found_multi = false;
if (PCI_FUNC(bdf) && !found_multi)
continue;
+
/* Check only the first access, we don't expect problems */
- ret = pci_bus_read_config(bus, bdf, PCI_HEADER_TYPE,
- &header_type, PCI_SIZE_8);
+ ret = pci_bus_read_config(bus, bdf, PCI_VENDOR_ID, &vendor,
+ PCI_SIZE_16);
if (ret)
goto error;
- pci_bus_read_config(bus, bdf, PCI_VENDOR_ID, &vendor,
- PCI_SIZE_16);
+
if (vendor == 0xffff || vendor == 0x0000)
continue;
+ pci_bus_read_config(bus, bdf, PCI_HEADER_TYPE,
+ &header_type, PCI_SIZE_8);
+
if (!PCI_FUNC(bdf))
found_multi = header_type & 0x80;
--
2.17.1
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