usb: xhci: add help function xhci_dequeue_td()

Add xhci_dequeue_td() helper function to reduce code duplication.

Function xhci_dequeue_td() advances the dequeue pointer past the specified
Transfer Descriptor (TD) and releases the TD.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241106101459.775897-30-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-ring.c

@@ -859,6 +859,16 @@ static void xhci_td_cleanup(struct xhci_hcd *xhci, struct xhci_td *td,
 	}
 }
 
+/* Give back previous TD and move on to the next TD. */
+static void xhci_dequeue_td(struct xhci_hcd *xhci, struct xhci_td *td, struct xhci_ring *ring,
+			    u32 status)
+{
+	ring->dequeue = td->end_trb;
+	ring->deq_seg = td->end_seg;
+	inc_deq(xhci, ring);
+
+	xhci_td_cleanup(xhci, td, ring, status);
+}
 
 /* Complete the cancelled URBs we unlinked from td_list. */
 static void xhci_giveback_invalidated_tds(struct xhci_virt_ep *ep)
@@ -2258,12 +2268,7 @@ static void finish_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 		break;
 	}
 
-	/* Update ring dequeue pointer */
-	ep_ring->dequeue = td->end_trb;
-	ep_ring->deq_seg = td->end_seg;
-	inc_deq(xhci, ep_ring);
-
-	xhci_td_cleanup(xhci, td, ep_ring, td->status);
+	xhci_dequeue_td(xhci, td, ep_ring, td->status);
 }
 
 /* sum trb lengths from the first trb up to stop_trb, _excluding_ stop_trb */
@@ -2496,12 +2501,7 @@ static void skip_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
 	/* calc actual length */
 	frame->actual_length = 0;
 
-	/* Update ring dequeue pointer */
-	ep->ring->dequeue = td->end_trb;
-	ep->ring->deq_seg = td->end_seg;
-	inc_deq(xhci, ep->ring);
-
-	xhci_td_cleanup(xhci, td, ep->ring, status);
+	xhci_dequeue_td(xhci, td, ep->ring, status);
 }
 
 /*
@@ -2791,10 +2791,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 
 	if (td && td->error_mid_td && !trb_in_td(xhci, td, ep_trb_dma, false)) {
 		xhci_dbg(xhci, "Missing TD completion event after mid TD error\n");
-		ep_ring->dequeue = td->end_trb;
-		ep_ring->deq_seg = td->end_seg;
-		inc_deq(xhci, ep_ring);
-		xhci_td_cleanup(xhci, td, ep_ring, td->status);
+		xhci_dequeue_td(xhci, td, ep_ring, td->status);
 	}
 
 	if (list_empty(&ep_ring->td_list)) {