From 9d7aba7786b6c9eec6d083e43fd639228c400c3a Mon Sep 17 00:00:00 2001 From: John Youn Date: Fri, 26 Aug 2016 18:43:01 -0700 Subject: [PATCH] Revert "usb: dwc3: gadget: always decrement by 1" This reverts commit 6f8245b4e37c ("usb: dwc3: gadget: always decrement by 1"). We can't always decrement this value. We should decrement only if the calculation of free slots results in a LINK TRB being among one of the free slots (dequeue < enqueue). Otherwise, if the LINK TRB is not among the free slots then it should not be decremented. Signed-off-by: John Youn Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 7a8d3d822b54..122e64df2f4d 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -884,9 +884,12 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep) return DWC3_TRB_NUM - 1; } - trbs_left = dep->trb_dequeue - dep->trb_enqueue - 1; + trbs_left = dep->trb_dequeue - dep->trb_enqueue; trbs_left &= (DWC3_TRB_NUM - 1); + if (dep->trb_dequeue < dep->trb_enqueue) + trbs_left--; + return trbs_left; }