[208/289] USB: ehci: disable LPM and PPCD for nVidia MCP89 chips

[Greg KH]

2.6.36-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Brian J. Tarricone <brian@xxxxxxxxxxxxx>

commit a85b4e7f4481c5a1ca89fa63c9c871151965075e upstream.

Tested on MacBookAir3,1.  Without this, we get EPROTO errors when
fetching device config descriptors.

Signed-off-by: Brian Tarricone <brian@xxxxxxxxxxxxx>
Reported-by: Benoit Gschwind <gschwind@xxxxxxxxxxx>
Tested-by: Edgar Hucek <gimli@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/host/ehci-pci.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -148,6 +148,18 @@ static int ehci_pci_setup(struct usb_hcd
 			if (pdev->revision < 0xa4)
 				ehci->no_selective_suspend = 1;
 			break;
+
+		/* MCP89 chips on the MacBookAir3,1 give EPROTO when
+		 * fetching device descriptors unless LPM is disabled.
+		 * There are also intermittent problems enumerating
+		 * devices with PPCD enabled.
+		 */
+		case 0x0d9d:
+			ehci_info(ehci, "disable lpm/ppcd for nvidia mcp89");
+			ehci->has_lpm = 0;
+			ehci->has_ppcd = 0;
+			ehci->command &= ~CMD_PPCEE;
+			break;
 		}
 		break;
 	case PCI_VENDOR_ID_VIA:


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