[PATCH] USB: EHCI and Freescale 83xx quirk

On the MPC834x processors the multiport host (MPH) EHCI controller has an
erratum in which the port number in the queue head expects to be 0..N-1
instead of 1..N.  If we are on one of these chips we subtract one from
the port number before putting it into the queue head.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 9b13bf2fa98d..6e28e593c044 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -721,7 +721,14 @@ qh_make (
                 info1 |= maxp << 16;
 
                 info2 |= (EHCI_TUNE_MULT_TT << 30);
-                info2 |= urb->dev->ttport << 23;
+
+                /* Some Freescale processors have an erratum in which the
+                 * port number in the queue head was 0..N-1 instead of 1..N.
+                 */
+                if (ehci_has_fsl_portno_bug(ehci))
+                        info2 |= (urb->dev->ttport-1) << 23;
+                else
+                        info2 |= urb->dev->ttport << 23;
 
                 /* set the address of the TT; for TDI's integrated
                  * root hub tt, leave it zeroed.