USB: ehci: disable LPM and PPCD for nVidia MCP89 chips

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

Signed-off-by: Brian Tarricone <brian@tarricone.org>
Reported-by: Benoit Gschwind <gschwind@gnu-log.net>
Tested-by: Edgar Hucek <gimli@dark-green.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 01bb72b..655f3c9 100644 (file)
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -161,6 +161,18 @@ static int ehci_pci_setup(struct usb_hcd *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: