USB: ehci potential oops fix on ARC/TDI cores

Kernel bugzilla entry #9569 reports a potential OOPS in some code
supporting the integrated root hub TT support used on ARC/TDI
derived cores.  (This seems to have been a longstanding issue.)

This patch cleans up usage of urb->dev->tt to avoid that potential
oops and also fixes some overly long lines.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 853e5e6396a5..776a97f33914 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -198,7 +198,8 @@ static int qtd_copy_status (
 
                 /* if async CSPLIT failed, try cleaning out the TT buffer */
                 if (status != -EPIPE
-                                && urb->dev->tt && !usb_pipeint (urb->pipe)
+                                && urb->dev->tt
+                                && !usb_pipeint(urb->pipe)
                                 && ((token & QTD_STS_MMF) != 0
                                         || QTD_CERR(token) == 0)
                                 && (!ehci_is_TDI(ehci)
@@ -211,6 +212,9 @@ static int qtd_copy_status (
                                 urb->dev->ttport, urb->dev->devnum,
                                 usb_pipeendpoint (urb->pipe), token);
 #endif /* DEBUG */
+                        /* REVISIT ARC-derived cores don't clear the root
+                         * hub TT buffer in this way...
+                         */
                         usb_hub_tt_clear_buffer (urb->dev, urb->pipe);
                 }
         }
@@ -638,6 +642,7 @@ qh_make (
         u32                     info1 = 0, info2 = 0;
         int                     is_input, type;
         int                     maxp = 0;
+        struct usb_tt           *tt = urb->dev->tt;
 
         if (!qh)
                 return qh;
@@ -661,8 +666,9 @@ qh_make (
          * For control/bulk requests, the HC or TT handles these.
          */
         if (type == PIPE_INTERRUPT) {
-                qh->usecs = NS_TO_US (usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,
-                                hb_mult (maxp) * max_packet (maxp)));
+                qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
+                                is_input, 0,
+                                hb_mult(maxp) * max_packet(maxp)));
                 qh->start = NO_FRAME;
 
                 if (urb->dev->speed == USB_SPEED_HIGH) {
@@ -680,7 +686,6 @@ qh_make (
                                 goto done;
                         }
                 } else {
-                        struct usb_tt   *tt = urb->dev->tt;
                         int             think_time;
 
                         /* gap is f(FS/LS transfer times) */
@@ -736,10 +741,8 @@ qh_make (
                 /* set the address of the TT; for TDI's integrated
                  * root hub tt, leave it zeroed.
                  */
-                if (!ehci_is_TDI(ehci)
-                                || urb->dev->tt->hub !=
-                                        ehci_to_hcd(ehci)->self.root_hub)
-                        info2 |= urb->dev->tt->hub->devnum << 16;
+                if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
+                        info2 |= tt->hub->devnum << 16;
 
                 /* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */