On Thu, 2017-12-21 at 14:41 +0800, Yong Wu wrote:

On Thu, 2017-12-21 at 10:11 +0800, honghui.zhang at mediatek.com wrote:

quoted

From: Honghui Zhang <redacted>

The host bridge of MT7622 has hardware code the class code to an
arbitrary, meaningless value, fix that.

Signed-off-by: Honghui Zhang <redacted>
---
 drivers/pci/host/pcie-mediatek.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
index 3248771..ae8d367 100644
--- a/drivers/pci/host/pcie-mediatek.c
+++ b/drivers/pci/host/pcie-mediatek.c

@@ -1174,3 +1174,15 @@ static struct platform_driver mtk_pcie_driver = {
 	},
 };
 builtin_platform_driver(mtk_pcie_driver);
+
+/* The host bridge of MT7622 advertises the wrong device class. */
+static void mtk_fixup_class(struct pci_dev *dev)
+{
+	dev->class = PCI_CLASS_BRIDGE_PCI << 8;
+}
+
+/*
+ * The HW default value of vendor id and device id for mt7622 are 0x0e8d,
+ * 0x3258, which are arbitrary, meaningless values.
+ */

What's the right vendor id and device id? is it possible to fix them
too?

Vendor ID is managed by PCI-SIG, you may get the assigned vendor ID
from:
https://pci-ids.ucw.cz/read/PC?restrict=

The vendor ID for Mediatek Corp. should be 14c3.
Device ID is something like vendor-defined.
Those values are in the configuration space and are read-only defined by
spec, it's been stored at the pci_dev, we may change the vendor and
device values in pci_dev, but I don't think it's necessary to change
that.
BTW, Does anyone really cares about the vendor ID and device ID except
the device's driver?

thanks.

quoted

+DECLARE_PCI_FIXUP_EARLY(0x0e8d, 0x3258, mtk_fixup_class);