[ 3.5.y.z extended stable ] Patch "USB: xhci - fix bit definitions for IMAN register" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Mon Mar 25 18:02:27 UTC 2013

This is a note to let you know that I have just added a patch titled

    USB: xhci - fix bit definitions for IMAN register

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



>From 5dc14ce39f02f6c676e3072406088344aec9c043 Mon Sep 17 00:00:00 2001
From: Dmitry Torokhov <dtor at vmware.com>
Date: Mon, 25 Feb 2013 10:56:01 -0800
Subject: [PATCH] USB: xhci - fix bit definitions for IMAN register

commit f8264340e694604863255cc0276491d17c402390 upstream.

According to XHCI specification ( the IP is bit 0 and IE is bit 1
of IMAN register. Previously their definitions were reversed.

Even though there are no ill effects being observed from the swapped
definitions (because IMAN_IP is RW1C and in legacy PCI case we come in
with it already set to 1 so it was clearing itself even though we were
setting IMAN_IE instead of IMAN_IP), we should still correct the values.

This patch should be backported to kernels as old as 2.6.36, that
contain the commit 4e833c0b87a30798e67f06120cecebef6ee9644c "xhci: don't
re-enable IE constantly".

Signed-off-by: Dmitry Torokhov <dtor at vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp at linux.intel.com>
Luis Henriques <luis.henriques at canonical.com>
 drivers/usb/host/xhci.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index b2a5527..b35bbbe 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -206,8 +206,8 @@ struct xhci_op_regs {
 /* bits 12:31 are reserved (and should be preserved on writes). */

 /* IMAN - Interrupt Management Register */
-#define IMAN_IP		(1 << 1)
-#define IMAN_IE		(1 << 0)
+#define IMAN_IE		(1 << 1)
+#define IMAN_IP		(1 << 0)

 /* USBSTS - USB status - status bitmasks */
 /* HC not running - set to 1 when run/stop bit is cleared. */

More information about the kernel-team mailing list