In accordance with specification, when sent data length is
an exact multiple of wMaxPacketSize for the pipe and less
than requested by host, the function shall return a zero-length
packet (ZLP) to indicate the end of the Data stage to a USB host.
Signed-off-by: Anton Tikhomirov <av.tikhomi...@samsung.com>
---
drivers/usb/dwc3/core.h | 2 ++
drivers/usb/dwc3/ep0.c | 27 ++++++++++++++++++++-------
drivers/usb/dwc3/gadget.c | 3 +++
3 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index f8af8d4..fefbf2d 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -619,6 +619,7 @@ struct dwc3_scratchpad_array {
* @three_stage_setup: set if we perform a three phase setup
* @ep0_bounced: true when we used bounce buffer
* @ep0_expect_in: true when we expect a DATA IN transfer
+ * @ep0_zlp_sent: true when ZLP was sent
* @start_config_issued: true when StartConfig command has been issued
* @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
* @needs_fifo_resize: not all users might want fifo resizing, flag it
@@ -700,6 +701,7 @@ struct dwc3 {
unsigned three_stage_setup:1;
unsigned ep0_bounced:1;
unsigned ep0_expect_in:1;
+ unsigned ep0_zlp_sent:1;
unsigned start_config_issued:1;
unsigned setup_packet_pending:1;
unsigned delayed_status:1;
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 21a3520..cf72561 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -782,6 +782,9 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
return;
}
+ if (dwc->ep0_zlp_sent)
+ goto finish_zlp;
+
length = trb->size & DWC3_TRB_SIZE_MASK;
if (dwc->ep0_bounced) {
@@ -802,14 +805,24 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
/* for some reason we did not get everything out */
dwc3_ep0_stall_and_restart(dwc);
- } else {
- /*
- * handle the case where we have to send a zero packet. This
- * seems to be case when req.length > maxpacket. Could it be?
- */
- if (r)
- dwc3_gadget_giveback(ep0, r, 0);
+ return;
}
+
+ /* handle the case where we have to send a zero packet */
+ if ((epnum & 1) && ur->zero &&
+ (ur->length % ep0->endpoint.maxpacket == 0)) {
+ int ret;
+
+ ret = dwc3_ep0_start_trans(dwc, epnum, dwc->ctrl_req_addr, 0,
+ DWC3_TRBCTL_CONTROL_DATA);
+ WARN_ON(ret < 0);
+ dwc->ep0_zlp_sent = 1;
+ return;
+ }
+
+finish_zlp:
+ if (r)
+ dwc3_gadget_giveback(ep0, r, 0);
}
static void dwc3_ep0_complete_status(struct dwc3 *dwc,
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 02e44fc..59ecd1e 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -251,6 +251,9 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct
dwc3_request *req,
usb_gadget_unmap_request(&dwc->gadget, &req->request,
req->direction);
+ if (dwc->ep0_zlp_sent && dep->number == 0)
+ dwc->ep0_zlp_sent = 0;
+
dev_dbg(dwc->dev, "request %p from %s completed %d/%d ===> %d\n",
req, dep->name, req->request.actual,
req->request.length, status);
--
1.7.9.5
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