When sent data length is equal to maximum packet size (MPS
= 64B for EP0), then a ZLP packet shall be sent to indicate
end of the transfer to a USB host.
Tested with:
- DFU gadget (various size of the sent data - also packet = MPS)
- Ethernet gadget (CDC and RNDIS)
- Multi Function Gadget (g_multi)
HW:
- Samsung's C210 Universal rev.0
Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/usb/gadget/s3c-hsotg.c | 26 ++++++++++++++++++++++++--
1 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 0492c20..89e49ce 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -1558,8 +1558,11 @@ static void s3c_hsotg_handle_outdone(struct s3c_hsotg *hsotg,
}
if (epnum == 0) {
+ /* Condition req->complete != s3c_hsotg_complete_setup says:
+ * send ZLP when we have an asynchronous request from gadget */
if (!was_setup && req->complete != s3c_hsotg_complete_setup)
s3c_hsotg_send_zlp(hsotg, hs_req);
+
}
s3c_hsotg_complete_request_lock(hsotg, hs_ep, hs_req, result);
@@ -1810,6 +1813,13 @@ static void s3c_hsotg_complete_in(struct s3c_hsotg *hsotg,
return;
}
+ /* Finish ZLP handling for IN EP0 transactions */
+ if (hsotg->eps[0].sent_zlp) {
+ dev_dbg(hsotg->dev, "zlp packet received\n");
+ s3c_hsotg_complete_request_lock(hsotg, hs_ep, hs_req, 0);
+ return;
+ }
+
/* Calculate the size of the transfer by checking how much is left
* in the endpoint size register and then working it out from
* the amount we loaded for the transfer.
@@ -1829,9 +1839,21 @@ static void s3c_hsotg_complete_in(struct s3c_hsotg *hsotg,
__func__, hs_req->req.actual, size_done);
hs_req->req.actual = size_done;
+ dev_dbg(hsotg->dev, "req->length:%d req->actual:%d\n",
+ hs_req->req.length, hs_req->req.actual);
- /* if we did all of the transfer, and there is more data left
- * around, then try restarting the rest of the request */
+ /* Check if dealing with Maximum Packet Size(MPS) IN transfer (EP0)
+ * When req.lenght == ep.maxpacket then send IN ZLP packet to
+ * inform host that no more data is available.
+ */
+ if (hs_req->req.length == hs_req->req.actual && hs_ep->index == 0
+ && hs_req->req.length == hs_ep->ep.maxpacket) {
+
+ dev_dbg(hsotg->dev, "ep0 zlp IN packet sent\n");
+ s3c_hsotg_send_zlp(hsotg, hs_req);
+
+ return;
+ }
if (!size_left && hs_req->req.actual < hs_req->req.length) {
dev_dbg(hsotg->dev, "%s trying more for req...\n", __func__);
--
1.7.2.3
--
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