diff options
| author | Hou Zhiqiang <Zhiqiang.Hou@nxp.com> | 2018-10-08 16:35:47 +0800 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2018-11-20 19:14:22 -0700 |
| commit | 2a87f7fdd599172879633faf33cae7005344d666 (patch) | |
| tree | cce5b9bdefdd2f5693fbce627e82da2522640a20 /drivers/pci | |
| parent | a3e1653ddeb02f39481eba572275016171e9670c (diff) | |
dm/pci: Change the first CFG read to Vendor ID in enumeration
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.Hou@nxp.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci-uclass.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c index 0c52337f33..2cf55cb743 100644 --- a/drivers/pci/pci-uclass.c +++ b/drivers/pci/pci-uclass.c @@ -774,16 +774,19 @@ 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; |