xhci: rename and simplify last_trb_on_last_seg() helper

It's only used with rings that have link trbs

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 64e24d2..21e1dd6 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -89,19 +89,6 @@ dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
        return seg->dma + (segment_offset * sizeof(*trb));
 }
 
-/* Does this link TRB point to the first segment in a ring,
- * or was the previous TRB the last TRB on the last segment in the ERST?
- */
-static bool last_trb_on_last_seg(struct xhci_hcd *xhci, struct xhci_ring *ring,
-               struct xhci_segment *seg, union xhci_trb *trb)
-{
-       if (ring == xhci->event_ring)
-               return (trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
-                       (seg->next == xhci->event_ring->first_seg);
-       else
-               return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
-}
-
 static bool trb_is_link(union xhci_trb *trb)
 {
        return TRB_TYPE_LINK_LE32(trb->link.control);
@@ -118,6 +105,11 @@ static bool last_trb_on_ring(struct xhci_ring *ring,
        return last_trb_on_seg(seg, trb) && (seg->next == ring->first_seg);
 }
 
+static bool link_trb_toggles_cycle(union xhci_trb *trb)
+{
+       return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
+}
+
 /* Updates trb to point to the next TRB in the ring, and updates seg if the next
  * TRB is in a new segment.  This does not skip over link TRBs, and it does not
  * effect the ring dequeue or enqueue pointers.
@@ -226,7 +218,7 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
                next->link.control ^= cpu_to_le32(TRB_CYCLE);
 
                /* Toggle the cycle bit after the last ring segment. */
-               if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next))
+               if (link_trb_toggles_cycle(next))
                        ring->cycle_state ^= 1;
 
                ring->enq_seg = ring->enq_seg->next;
@@ -2885,36 +2877,29 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
                }
        }
 
-       if (trb_is_link(ep_ring->enqueue)) {
-               struct xhci_ring *ring = ep_ring;
-               union xhci_trb *next;
-
-               next = ring->enqueue;
+       while (trb_is_link(ep_ring->enqueue)) {
+               /* If we're not dealing with 0.95 hardware or isoc rings
+                * on AMD 0.96 host, clear the chain bit.
+                */
+               if (!xhci_link_trb_quirk(xhci) &&
+                   !(ep_ring->type == TYPE_ISOC &&
+                     (xhci->quirks & XHCI_AMD_0x96_HOST)))
+                       ep_ring->enqueue->link.control &=
+                               cpu_to_le32(~TRB_CHAIN);
+               else
+                       ep_ring->enqueue->link.control |=
+                               cpu_to_le32(TRB_CHAIN);
 
-               while (trb_is_link(next)) {
-                       /* If we're not dealing with 0.95 hardware or isoc rings
-                        * on AMD 0.96 host, clear the chain bit.
-                        */
-                       if (!xhci_link_trb_quirk(xhci) &&
-                                       !(ring->type == TYPE_ISOC &&
-                                        (xhci->quirks & XHCI_AMD_0x96_HOST)))
-                               next->link.control &= cpu_to_le32(~TRB_CHAIN);
-                       else
-                               next->link.control |= cpu_to_le32(TRB_CHAIN);
+               wmb();
+               ep_ring->enqueue->link.control ^= cpu_to_le32(TRB_CYCLE);
 
-                       wmb();
-                       next->link.control ^= cpu_to_le32(TRB_CYCLE);
+               /* Toggle the cycle bit after the last ring segment. */
+               if (link_trb_toggles_cycle(ep_ring->enqueue))
+                       ep_ring->cycle_state ^= 1;
 
-                       /* Toggle the cycle bit after the last ring segment. */
-                       if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
-                               ring->cycle_state ^= 1;
-                       }
-                       ring->enq_seg = ring->enq_seg->next;
-                       ring->enqueue = ring->enq_seg->trbs;
-                       next = ring->enqueue;
-               }
+               ep_ring->enq_seg = ep_ring->enq_seg->next;
+               ep_ring->enqueue = ep_ring->enq_seg->trbs;
        }
-
        return 0;
 }