From 21c3ee93867694e8c7382ff77b4645b50d3233e9 Mon Sep 17 00:00:00 2001
From: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Date: Tue, 15 Sep 2015 16:55:29 +0200
Subject: [PATCH] usb: gadget: dummy_hcd: emulate sending zlp in packet logic
currently, when a zlp flag is set and an urb/usb_request
buffer is filled without a short packet, transfer() leaves
its status at -EINPROGRESS and does not rescan for short
packet.
In a scenario where ep.maxpacket bytes are copied,
URB_ZERO_PACKET is set, urb buffer is filled and usb_request
buffer is not, transfer() returns with an urb with
-EINPROGRESS status, which dummy_hcd treats as incomplete
transfer.
Check for zlp and rescan appropriately.
Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/gadget/udc/dummy_hcd.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index 1379ad40d864b..93b38f88e7b2c 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -1429,15 +1429,24 @@ static int transfer(struct dummy_hcd *dum_hcd, struct urb *urb,
req->req.status = 0;
}
- /* many requests terminate without a short packet */
+ /*
+ * many requests terminate without a short packet.
+ * send a zlp if demanded by flags.
+ */
} else {
- if (req->req.length == req->req.actual
- && !req->req.zero)
- req->req.status = 0;
- if (urb->transfer_buffer_length == urb->actual_length
- && !(urb->transfer_flags
- & URB_ZERO_PACKET))
- *status = 0;
+ if (req->req.length == req->req.actual) {
+ if (req->req.zero && to_host)
+ rescan = 1;
+ else
+ req->req.status = 0;
+ }
+ if (urb->transfer_buffer_length == urb->actual_length) {
+ if (urb->transfer_flags & URB_ZERO_PACKET &&
+ !to_host)
+ rescan = 1;
+ else
+ *status = 0;
+ }
}
/* device side completion --> continuable */
--
GitLab