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>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0c934a1..1de4d3f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -61,6 +61,11 @@
{
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 @@
{
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