[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>

3 files changed, 33 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index c6012d6cd527..59f90f76ee31 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -198,6 +198,16 @@ static void mpc83xx_usb_setup(struct usb_hcd *hcd)
                 mpc83xx_setup_phy(ehci, pdata->phy_mode, 0);
 
         if (pdata->operating_mode == FSL_USB2_MPH_HOST) {
+                unsigned int chip, rev, svr;
+
+                svr = mfspr(SPRN_SVR);
+                chip = svr >> 16;
+                rev = (svr >> 4) & 0xf;
+
+                /* Deal with USB Erratum #14 on MPC834x Rev 1.0 & 1.1 chips */
+                if ((rev == 1) && (chip >= 0x8050) && (chip <= 0x8055))
+                        ehci->has_fsl_port_bug = 1;
+
                 if (pdata->port_enables & FSL_USB2_PORT0_ENABLED)
                         mpc83xx_setup_phy(ehci, pdata->phy_mode, 0);
                 if (pdata->port_enables & FSL_USB2_PORT1_ENABLED)
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.
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 86af41c41de1..679c1cdcc915 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -88,8 +88,11 @@ struct ehci_hcd {			/* one per controller */
         unsigned long           next_statechange;
         u32                     command;
 
+        /* SILICON QUIRKS */
         unsigned                is_tdi_rh_tt:1; /* TDI roothub with TT */
         unsigned                no_selective_suspend:1;
+        unsigned                has_fsl_port_bug:1; /* FreeScale */
+
         u8                      sbrn;           /* packed release number */
 
         /* irq statistics */
@@ -639,6 +642,18 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc)
 
 /*-------------------------------------------------------------------------*/
 
+#ifdef CONFIG_PPC_83xx
+/* Some Freescale processors have an erratum in which the TT
+ * port number in the queue head was 0..N-1 instead of 1..N.
+ */
+#define ehci_has_fsl_portno_bug(e)              ((e)->has_fsl_port_bug)
+#else
+#define ehci_has_fsl_portno_bug(e)              (0)
+#endif
+
+
+/*-------------------------------------------------------------------------*/
+
 #ifndef DEBUG
 #define STUB_DEBUG_FILES
 #endif  /* DEBUG */