linux-kernel - [PATCH] ehci: disable LPM and PPCD for nVidia MCP89 chips

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Sat, 20 Nov 2010 16:32:55 -0800
From:	"Brian J. Tarricone" <brian@...ricone.org>
To:	linux-kernel@...r.kernel.org
Cc:	Brian Tarricone <brian@...ricone.org>,
	Greg Kroah-Hartman <greg@...ah.com>
Subject: [PATCH] ehci: disable LPM and PPCD for nVidia MCP89 chips

From: Brian Tarricone <brian@...ricone.org>

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

Signed-off-by: Brian Tarricone <brian@...ricone.org>
Reported-by: Benoit Gschwind <gschwind@...-log.net>
Tested-by: Edgar Hucek <gimli@...k-green.com>
Cc: Greg Kroah-Hartman <greg@...ah.com>
---
 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/