From: John Youn <johnyoun@synopsys.com>
Date: Fri, 20 May 2016 00:26:15 +0000 (-0700)
Subject: UPSTREAM: usb: dwc3: gadget: Account for link TRB in TRBs left
X-Git-Tag: firefly_0821_release~1801
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bf8f5fbf04f17ac64b2cc4e87701a931e9922fe5;p=firefly-linux-kernel-4.4.55.git

UPSTREAM: usb: dwc3: gadget: Account for link TRB in TRBs left

The TRBs left calculation didn't account for the link TRB taking up one
spot.

If the trb_dequeue < trb_enqueue, then the result includes the link
TRB slot so it must be adjusted.

Change-Id: If03f89ea1f523b4bce1b5f096ae81aebc891c63f
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Wu Liang feng <wulf@rock-chips.com>
(cherry picked from commit 7d0a038b130cde7265d6bbc5e148734cb127f341)
---

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 09f61997b657..f027d4b32997 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -868,6 +868,9 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
 	trbs_left = dep->trb_dequeue - dep->trb_enqueue;
 	trbs_left %= DWC3_TRB_NUM;
 
+	if (dep->trb_dequeue < dep->trb_enqueue)
+		trbs_left--;
+
 	return trbs_left;
 }