From 78c58a53c9864447f2a46d4c06dd3c2616823ad2 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 31 Aug 2011 17:12:02 +0200
Subject: [PATCH] usb: dwc3: gadget: do not map/unmap ZLP transfers
If the gadget drivers sends a ZLP we are trying to map this this request
which does not work on all implementations. So we simply skip mapping
it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/dwc3/gadget.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0c934a195deb8..1de4d3f875698 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -61,6 +61,11 @@ void dwc3_map_buffer_to_dma(struct dwc3_request *req)
{
struct dwc3 *dwc = req->dep->dwc;
+ if (req->request.length == 0) {
+ /* req->request.dma = dwc->setup_buf_addr; */
+ return;
+ }
+
if (req->request.dma == DMA_ADDR_INVALID) {
req->request.dma = dma_map_single(dwc->dev, req->request.buf,
req->request.length, req->direction
@@ -78,6 +83,11 @@ void dwc3_unmap_buffer_from_dma(struct dwc3_request *req)
{
struct dwc3 *dwc = req->dep->dwc;
+ if (req->request.length == 0) {
+ req->request.dma = DMA_ADDR_INVALID;
+ return;
+ }
+
if (req->mapped) {
dma_unmap_single(dwc->dev, req->request.dma,
req->request.length, req->direction
--
2.39.5