usb: xhci: avoid unnecessary calculation
No need to calculate remainder and length_field, if there is
no data phase of a control transfer.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 61b5fea..2374a13 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3237,7 +3237,7 @@
struct usb_ctrlrequest *setup;
struct xhci_generic_trb *start_trb;
int start_cycle;
- u32 field, length_field, remainder;
+ u32 field;
struct urb_priv *urb_priv;
struct xhci_td *td;
@@ -3310,16 +3310,16 @@
else
field = TRB_TYPE(TRB_DATA);
- remainder = xhci_td_remainder(xhci, 0,
- urb->transfer_buffer_length,
- urb->transfer_buffer_length,
- urb, 1);
-
- length_field = TRB_LEN(urb->transfer_buffer_length) |
- TRB_TD_SIZE(remainder) |
- TRB_INTR_TARGET(0);
-
if (urb->transfer_buffer_length > 0) {
+ u32 length_field, remainder;
+
+ remainder = xhci_td_remainder(xhci, 0,
+ urb->transfer_buffer_length,
+ urb->transfer_buffer_length,
+ urb, 1);
+ length_field = TRB_LEN(urb->transfer_buffer_length) |
+ TRB_TD_SIZE(remainder) |
+ TRB_INTR_TARGET(0);
if (setup->bRequestType & USB_DIR_IN)
field |= TRB_DIR_IN;
queue_trb(xhci, ep_ring, true,