usb: xhci: remove enq_updates and deq_updates from ring

enq_updates and deq_updates were introduced in the first place
to check whether an xhci hardware is able to respond to trbs
enqueued in the ring. We now have trb tracers to trace every
single enqueue/dequeue trb. It's time to remove them and the
associated debugging code.
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>

drivers/usb/host/xhci-dbg.c

@@ -347,14 +347,10 @@ void xhci_dbg_ring_ptrs(struct xhci_hcd *xhci, struct xhci_ring *ring)
 			ring->dequeue,
 			(unsigned long long)xhci_trb_virt_to_dma(ring->deq_seg,
 							    ring->dequeue));
-	xhci_dbg(xhci, "Ring deq updated %u times\n",
-			ring->deq_updates);
 	xhci_dbg(xhci, "Ring enq = %p (virt), 0x%llx (dma)\n",
 			ring->enqueue,
 			(unsigned long long)xhci_trb_virt_to_dma(ring->enq_seg,
 							    ring->enqueue));
-	xhci_dbg(xhci, "Ring enq updated %u times\n",
-			ring->enq_updates);
 }
 
 /**
@@ -373,10 +369,6 @@ void xhci_debug_ring(struct xhci_hcd *xhci, struct xhci_ring *ring)
 	struct xhci_segment *first_seg = ring->first_seg;
 	xhci_debug_segment(xhci, first_seg);
 
-	if (!ring->enq_updates && !ring->deq_updates) {
-		xhci_dbg(xhci, "  Ring has not been updated\n");
-		return;
-	}
 	for (seg = first_seg->next; seg != first_seg; seg = seg->next)
 		xhci_debug_segment(xhci, seg);
 }

drivers/usb/host/xhci-mem.c

@@ -315,9 +315,6 @@ static void xhci_initialize_ring_info(struct xhci_ring *ring,
 	 * handling ring expansion, set the cycle state equal to the old ring.
 	 */
 	ring->cycle_state = cycle_state;
-	/* Not necessary for new rings, but needed for re-initialized rings */
-	ring->enq_updates = 0;
-	ring->deq_updates = 0;
 
 	/*
 	 * Each segment has a link TRB, and leave an extra TRB for SW

drivers/usb/host/xhci-ring.c

@@ -167,8 +167,6 @@ static void next_trb(struct xhci_hcd *xhci,
  */
 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring)
 {
-	ring->deq_updates++;
-
 	/* event ring doesn't have link trbs, check for last trb */
 	if (ring->type == TYPE_EVENT) {
 		if (!last_trb_on_seg(ring->deq_seg, ring->dequeue)) {
@@ -226,7 +224,6 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
 		ring->num_trbs_free--;
 	next = ++(ring->enqueue);
 
-	ring->enq_updates++;
 	/* Update the dequeue pointer further if that was a link TRB */
 	while (trb_is_link(next)) {
 

drivers/usb/host/xhci.h

@@ -1566,10 +1566,8 @@ struct xhci_ring {
 	struct xhci_segment	*last_seg;
 	union  xhci_trb		*enqueue;
 	struct xhci_segment	*enq_seg;
-	unsigned int		enq_updates;
 	union  xhci_trb		*dequeue;
 	struct xhci_segment	*deq_seg;
-	unsigned int		deq_updates;
 	struct list_head	td_list;
 	/*
 	 * Write the cycle state into the TRB cycle field to give ownership of