On Sat, Jul 18, 2020 at 05:39:36PM +0800, Tiezhu Yang wrote:
> According to the datasheet of Loongson LS7A bridge chip, the old version
> of Loongson LS7A PCIE port has a wrong value about PCI class which is
> 0x060000, the correct value should be 0x060400, this bug can be fixed by
> "dev->class = PCI_CLASS_BRIDGE_PCI << 8;" at the software level. As far
> as I know, the latest version of LS7A has already fixed the value at the
> hardware level.
>
> In order to maintain downward compatibility, use DECLARE_PCI_FIXUP_EARLY
> instead of DECLARE_PCI_FIXUP_HEADER for bridge_class_quirk() to fix it as
> early as possible.
>
> Otherwise, in the function pci_setup_device(), the related code about
> "dev->class" such as "class = dev->class >> 8;" and "dev->transparent
> = ((dev->class & 0xff) == 1);" maybe get wrong value without EARLY fixup.
>
> Fixes: 1f58cca5cf2b ("PCI: Add Loongson PCI Controller support")
> Signed-off-by: Tiezhu Yang <yangtie...@loongson.cn>
> ---
>
> v2: Modify the patch subject used with lower case "loongson"
>
> v3: Update the commit message
>
> v4: Update the commit message to describe the bug
>
> v5: Remove "due to" in the commit message suggested by Sergei Shtylyov
>
> drivers/pci/controller/pci-loongson.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Applied to pci/loongson, thanks.
Lorenzo
> diff --git a/drivers/pci/controller/pci-loongson.c
> b/drivers/pci/controller/pci-loongson.c
> index 459009c..58b862a 100644
> --- a/drivers/pci/controller/pci-loongson.c
> +++ b/drivers/pci/controller/pci-loongson.c
> @@ -37,11 +37,11 @@ static void bridge_class_quirk(struct pci_dev *dev)
> {
> dev->class = PCI_CLASS_BRIDGE_PCI << 8;
> }
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LOONGSON,
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
> DEV_PCIE_PORT_0, bridge_class_quirk);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LOONGSON,
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
> DEV_PCIE_PORT_1, bridge_class_quirk);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LOONGSON,
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
> DEV_PCIE_PORT_2, bridge_class_quirk);
>
> static void system_bus_quirk(struct pci_dev *pdev)
> --
> 2.1.0
>
