usb: xhci: Fix TRB transfer length macro used for Event TRB.

Use proper macro while extracting TRB transfer length from
Transfer event TRBs. Adding a macro EVENT_TRB_LEN (bits 0:23)
for the same, and use it instead of TRB_LEN (bits 0:16) in
case of event TRBs.

This patch should be backported to kernels as old as 2.6.31, that
contain the commit b10de142119a676552df3f0d2e3a9d647036c26a "USB: xhci:
Bulk transfer support".  This patch will have issues applying to older
kernels.

Signed-off-by: Vivek gautam <gautam.vivek@samsung.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

2 files changed, 16 insertions, 12 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index ec2681918682..9652dae95942 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2029,8 +2029,8 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
                 if (event_trb != ep_ring->dequeue &&
                                 event_trb != td->last_trb)
                         td->urb->actual_length =
-                                td->urb->transfer_buffer_length
-                                - TRB_LEN(le32_to_cpu(event->transfer_len));
+                                td->urb->transfer_buffer_length -
+                                EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
                 else
                         td->urb->actual_length = 0;
 
@@ -2062,7 +2062,7 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
                 /* Maybe the event was for the data stage? */
                         td->urb->actual_length =
                                 td->urb->transfer_buffer_length -
-                                TRB_LEN(le32_to_cpu(event->transfer_len));
+                                EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
                         xhci_dbg(xhci, "Waiting for status "
                                         "stage event\n");
                         return 0;
@@ -2098,7 +2098,7 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
         /* handle completion code */
         switch (trb_comp_code) {
         case COMP_SUCCESS:
-                if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) {
+                if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) {
                         frame->status = 0;
                         break;
                 }
@@ -2143,7 +2143,7 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
                                 len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));
                 }
                 len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
-                        TRB_LEN(le32_to_cpu(event->transfer_len));
+                        EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
 
                 if (trb_comp_code != COMP_STOP_INVAL) {
                         frame->actual_length = len;
@@ -2201,7 +2201,7 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
         case COMP_SUCCESS:
                 /* Double check that the HW transferred everything. */
                 if (event_trb != td->last_trb ||
-                                TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
+                    EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
                         xhci_warn(xhci, "WARN Successful completion "
                                         "on short TX\n");
                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
@@ -2229,18 +2229,18 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
                                 "%d bytes untransferred\n",
                                 td->urb->ep->desc.bEndpointAddress,
                                 td->urb->transfer_buffer_length,
-                                TRB_LEN(le32_to_cpu(event->transfer_len)));
+                                EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));
         /* Fast path - was this the last TRB in the TD for this URB? */
         if (event_trb == td->last_trb) {
-                if (TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
+                if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
                         td->urb->actual_length =
                                 td->urb->transfer_buffer_length -
-                                TRB_LEN(le32_to_cpu(event->transfer_len));
+                                EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
                         if (td->urb->transfer_buffer_length <
                                         td->urb->actual_length) {
                                 xhci_warn(xhci, "HC gave bad length "
                                                 "of %d bytes left\n",
-                                          TRB_LEN(le32_to_cpu(event->transfer_len)));
+                                          EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));
                                 td->urb->actual_length = 0;
                                 if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
                                         *status = -EREMOTEIO;
@@ -2282,7 +2282,7 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
                 if (trb_comp_code != COMP_STOP_INVAL)
                         td->urb->actual_length +=
                                 TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
-                                TRB_LEN(le32_to_cpu(event->transfer_len));
+                                EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
         }
 
         return finish_td(xhci, td, event_trb, event, ep, status, false);
@@ -2370,7 +2370,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
          * transfer type
          */
         case COMP_SUCCESS:
-                if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
+                if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
                         break;
                 if (xhci->quirks & XHCI_TRUST_TX_LENGTH)
                         trb_comp_code = COMP_SHORT_TX;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index d798b6931914..63582719e0fb 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -972,6 +972,10 @@ struct xhci_transfer_event {
         __le32  flags;
 };
 
+/* Transfer event TRB length bit mask */
+/* bits 0:23 */
+#define EVENT_TRB_LEN(p)                ((p) & 0xffffff)
+
 /** Transfer Event bit fields **/
 #define TRB_TO_EP_ID(p) (((p) >> 16) & 0x1f)