From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754164Ab0KUAdT (ORCPT ); Sat, 20 Nov 2010 19:33:19 -0500 Received: from mail-gw0-f46.google.com ([74.125.83.46]:63280 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303Ab0KUAdS (ORCPT ); Sat, 20 Nov 2010 19:33:18 -0500 From: "Brian J. Tarricone" To: linux-kernel@vger.kernel.org Cc: Brian Tarricone , Greg Kroah-Hartman Subject: [PATCH] ehci: disable LPM and PPCD for nVidia MCP89 chips Date: Sat, 20 Nov 2010 16:32:55 -0800 Message-Id: <1290299575-15911-1-git-send-email-brian@tarricone.org> X-Mailer: git-send-email 1.7.3.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Brian Tarricone Tested on MacBookAir3,1. Without this, we get EPROTO errors when fetching device config descriptors. Signed-off-by: Brian Tarricone Reported-by: Benoit Gschwind Tested-by: Edgar Hucek Cc: Greg Kroah-Hartman --- drivers/usb/host/ehci-pci.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index a1e8d27..aa79f98 100644 --- 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 *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: -- 1.7.2.2