Commit d0c77d84 authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
Browse files

xhci: rename and simplify last_trb_on_last_seg() helper 



It's only used with rings that have link trbs

Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 549310ab

drivers/usb/host/xhci-ring.c

+25 −40
Original line number Diff line number Diff line
@@ -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(next)) {

	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) &&

					!(ring->type == TYPE_ISOC &&

		    !(ep_ring->type == TYPE_ISOC &&

		      (xhci->quirks & XHCI_AMD_0x96_HOST)))

				next->link.control &= cpu_to_le32(~TRB_CHAIN);

			ep_ring->enqueue->link.control &=

				cpu_to_le32(~TRB_CHAIN);

		else

				next->link.control |= cpu_to_le32(TRB_CHAIN);

			ep_ring->enqueue->link.control |=

				cpu_to_le32(TRB_CHAIN);



		wmb();

			next->link.control ^= cpu_to_le32(TRB_CYCLE);

		ep_ring->enqueue->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)) {

				ring->cycle_state ^= 1;

			}

			ring->enq_seg = ring->enq_seg->next;

			ring->enqueue = ring->enq_seg->trbs;

			next = ring->enqueue;

		}

	}

		if (link_trb_toggles_cycle(ep_ring->enqueue))

			ep_ring->cycle_state ^= 1;



		ep_ring->enq_seg = ep_ring->enq_seg->next;

		ep_ring->enqueue = ep_ring->enq_seg->trbs;

	}

	return 0;

}