From 29e7fc19ceda9d93fba21a35990e2eb157901010 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Tue, 3 Mar 2015 17:32:13 +0100 Subject: [PATCH] usb: dwc3: gadget: Set all ctrl fields of Transfer Control Blocks (TRB) to be LST It turned out that current dwc3 gadget code is preparing multiple TRBs for a transfer. Unfortunately, when multiple requests are in the same queue, only for the last one the LST (last) ctrl bit is set. Due to that dwc3 HW executes all TRBs up till the one marked as last. Unfortunately, UMS requires call of ->complete callback after any send TRB. This is the reason for "hangs" in executing UMS. This code simplifies this situation and set each TRB's ctrl field bit to be last (LST bit). Signed-off-by: Lukasz Majewski --- drivers/usb/dwc3/gadget.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index eb31cd9..a8335b3 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -789,7 +789,6 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting) struct dwc3_request *req, *n; u32 trbs_left; u32 max; - unsigned int last_one = 0; BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM); @@ -839,24 +838,14 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting) list_for_each_entry_safe(req, n, &dep->request_list, list) { unsigned length; dma_addr_t dma; - last_one = false; dma = req->request.dma; length = req->request.length; - trbs_left--; - - if (!trbs_left) - last_one = 1; - - /* Is this the last request? */ - if (list_is_last(&req->list, &dep->request_list)) - last_one = 1; dwc3_prepare_one_trb(dep, req, dma, length, - last_one, false, 0); + true, false, 0); - if (last_one) - break; + break; } } -- 2.7.4