diff mbox

[for,4.14] xhci: allow TRACE to work with EVENT ring dequeue

Message ID 1506100859-14521-1-git-send-email-awallis@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Adam Wallis Sept. 22, 2017, 5:20 p.m. UTC
inc_deq() currently bails earlier for EVENT rings than the common return
point of the function, due to the fact that EVENT rings do not have
link TRBs. The unfortunate side effect of this is that the very useful
trace_xhci_inc_deq() function is not called/usable for EVENT ring
debug.

This patch provides a refactor by removing the multiple return exit
points into a single return which additionally allows for all rings to
use the trace function.

Signed-off-by: Adam Wallis <awallis@codeaurora.org>
---
 drivers/usb/host/xhci-ring.c | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)
diff mbox

Patch

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index a944365..10afd50 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -171,25 +171,24 @@  static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring)
 	if (ring->type == TYPE_EVENT) {
 		if (!last_trb_on_seg(ring->deq_seg, ring->dequeue)) {
 			ring->dequeue++;
-			return;
+		} else {
+			if (last_trb_on_ring(ring, ring->deq_seg,
+				ring->dequeue))
+				ring->cycle_state ^= 1;
+			ring->deq_seg = ring->deq_seg->next;
+			ring->dequeue = ring->deq_seg->trbs;
+		}
+	} else {
+		/* All other rings have link trbs */
+		if (!trb_is_link(ring->dequeue)) {
+			ring->dequeue++;
+			ring->num_trbs_free++;
+		}
+		while (trb_is_link(ring->dequeue)) {
+			ring->deq_seg = ring->deq_seg->next;
+			ring->dequeue = ring->deq_seg->trbs;
 		}
-		if (last_trb_on_ring(ring, ring->deq_seg, ring->dequeue))
-			ring->cycle_state ^= 1;
-		ring->deq_seg = ring->deq_seg->next;
-		ring->dequeue = ring->deq_seg->trbs;
-		return;
-	}
-
-	/* All other rings have link trbs */
-	if (!trb_is_link(ring->dequeue)) {
-		ring->dequeue++;
-		ring->num_trbs_free++;
-	}
-	while (trb_is_link(ring->dequeue)) {
-		ring->deq_seg = ring->deq_seg->next;
-		ring->dequeue = ring->deq_seg->trbs;
 	}
-
 	trace_xhci_inc_deq(ring);
 
 	return;