PCI: Revert aeb30016 ("PCI: add Intel USB specific reset method")

Revert aeb30016 ("PCI: add Intel USB specific reset method").

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.

I considered adding a shift, but I can't test it, so it's as likely to
break something as to fix something.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Yu Zhao <yu.zhao@intel.com>
CC: Mathias Nyman <mathias.nyman@intel.com>

drivers/pci/quirks.c

@@ -3344,28 +3344,6 @@ fs_initcall_sync(pci_apply_final_quirks);
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */
-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) {
-		pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
-		if (!pos)
-			return -ENOTTY;
-
-		if (probe)
-			return 0;
-
-		pci_write_config_byte(dev, pos + 0x4, 1);
-		msleep(100);
-
-		return 0;
-	} else {
-		return -ENOTTY;
-	}
-}
-
 static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
 {
 	/*
@@ -3524,8 +3502,6 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
 		reset_ivb_igd },
 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA,
 		reset_ivb_igd },
-	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
-		reset_intel_generic_dev },
 	{ PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
 		reset_chelsio_generic_dev },
 	{ 0 }