patches/0253-xhci-allow-TRACE-to-work-with-EVENT-ring-dequeue.patch

From a8c2b0929f10346e095fdc1fb0964a01e3db18fc Mon Sep 17 00:00:00 2001
From: Adam Wallis <awallis@codeaurora.org>
Date: Thu, 5 Oct 2017 11:21:47 +0300
Subject: [PATCH 0253/1795] xhci: allow TRACE to work with EVENT ring dequeue

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>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 49d5b05e191d4486c125ff00a01fc5e9e7ba452c)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/usb/host/xhci-ring.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 91cab441b82f..d5f44776b360 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -172,13 +172,13 @@ 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;
+			goto out;
 		}
 		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;
+		goto out;
 	}
 
 	/* All other rings have link trbs */
@@ -191,6 +191,7 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring)
 		ring->dequeue = ring->deq_seg->trbs;
 	}
 
+out:
 	trace_xhci_inc_deq(ring);
 
 	return;
-- 
2.19.0