[PATCH 09/22] usb: dwc3: gadget: split __dwc3_gadget_kick_transfer()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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 <felipe.balbi@xxxxxxxxxxxxxxx>
---
 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 eca131f0be59..adf743bca36f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -881,6 +881,65 @@ 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
@@ -893,70 +952,19 @@ 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;
 	}
 }
 
-- 
2.8.2

---------------------------------------------------------------------
Intel Finland Oy
Registered Address: PL 281, 00181 Helsinki 
Business Identity Code: 0357606 - 4 
Domiciled in Helsinki 

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux