From 5ee85d890f8de5c6f1ab22ba13734a63fdf3ff2d Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Fri, 13 May 2016 12:42:44 +0300 Subject: [PATCH] usb: dwc3: gadget: split __dwc3_gadget_kick_transfer() To aid code readability, we're gonna split __dwc3_gadget_kick_transfer() into its constituent parts: scatter gather and linear buffers. That way, it's easier to follow the code and focus debug effort when one or the other fails. Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 122 ++++++++++++++++++++------------------ 1 file changed, 65 insertions(+), 57 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 4c9fe7b55100..bff2c35f37a8 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -903,6 +903,65 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep) return dep->trb_dequeue - dep->trb_enqueue; } +static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, + struct dwc3_request *req, unsigned int trbs_left) +{ + struct usb_request *request = &req->request; + struct scatterlist *sg = request->sg; + struct scatterlist *s; + unsigned int last = false; + unsigned int length; + dma_addr_t dma; + int i; + + for_each_sg(sg, s, request->num_mapped_sgs, i) { + unsigned chain = true; + + length = sg_dma_len(s); + dma = sg_dma_address(s); + + if (sg_is_last(s)) { + if (list_is_last(&req->list, &dep->pending_list)) + last = true; + + chain = false; + } + + if (!trbs_left) + last = true; + + if (last) + chain = false; + + dwc3_prepare_one_trb(dep, req, dma, length, + last, chain, i); + + if (last) + break; + } +} + +static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, + struct dwc3_request *req, unsigned int trbs_left) +{ + unsigned int last = false; + unsigned int length; + dma_addr_t dma; + + dma = req->request.dma; + length = req->request.length; + + if (!trbs_left) + last = true; + + /* Is this the last request? */ + if (list_is_last(&req->list, &dep->pending_list)) + last = true; + + dwc3_prepare_one_trb(dep, req, dma, length, + last, false, 0); +} + /* * dwc3_prepare_trbs - setup TRBs from requests * @dep: endpoint for which requests are being prepared @@ -915,70 +974,19 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep) { struct dwc3_request *req, *n; u32 trbs_left; - unsigned int last_one = 0; BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM); trbs_left = dwc3_calc_trbs_left(dep); list_for_each_entry_safe(req, n, &dep->pending_list, list) { - unsigned length; - dma_addr_t dma; - last_one = false; - - if (req->request.num_mapped_sgs > 0) { - struct usb_request *request = &req->request; - struct scatterlist *sg = request->sg; - struct scatterlist *s; - int i; - - for_each_sg(sg, s, request->num_mapped_sgs, i) { - unsigned chain = true; - - length = sg_dma_len(s); - dma = sg_dma_address(s); - - if (sg_is_last(s)) { - if (list_is_last(&req->list, &dep->pending_list)) - last_one = true; - - chain = false; - } - - trbs_left--; - if (!trbs_left) - last_one = true; - - if (last_one) - chain = false; - - dwc3_prepare_one_trb(dep, req, dma, length, - last_one, chain, i); - - if (last_one) - break; - } - - if (last_one) - break; - } else { - dma = req->request.dma; - length = req->request.length; - trbs_left--; - - if (!trbs_left) - last_one = true; - - /* Is this the last request? */ - if (list_is_last(&req->list, &dep->pending_list)) - last_one = true; - - dwc3_prepare_one_trb(dep, req, dma, length, - last_one, false, 0); + if (req->request.num_mapped_sgs > 0) + dwc3_prepare_one_trb_sg(dep, req, trbs_left--); + else + dwc3_prepare_one_trb_linear(dep, req, trbs_left--); - if (last_one) - break; - } + if (!trbs_left) + return; } } -- 2.20.1