We checked for "dev->class == PCI_CLASS_SERIAL_USB", but dev->class
contains the entire three-byte base class/sub-class/interface, while
PCI_CLASS_SERIAL_USB is only the two-byte base class/sub-class.
This error meant that we used the Intel device-specific reset on devices
with class code 0x000c03 instead of those with class code 0x0c03xx.
0x000c03 is a reserved value in the 0x00 backwards compatibility base class
and shouldn't match any devices, so I think reset_intel_generic_dev()
always failed.
Shift dev->class to discard the interface byte before comparing with
PCI_CLASS_SERIAL_USB.
Fixes: aeb30016fec3 ("PCI: add Intel USB specific reset method")
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: Dexuan Cui <dexuan.cui@xxxxxxxxx>
CC: Yu Zhao <yu.zhao@xxxxxxxxx>
---
drivers/pci/quirks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 8bc60c2..356a401 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3358,7 +3358,7 @@ static int reset_intel_generic_dev(struct pci_dev *dev, int probe)
int pos;
/* only implement PCI_CLASS_SERIAL_USB at present */
- if (dev->class == PCI_CLASS_SERIAL_USB) {
+ if ((dev->class >> 8) == PCI_CLASS_SERIAL_USB) {
pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
if (!pos)
return -ENOTTY;
--
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