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
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -161,6 +161,18 @@
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: