[ 158/262] usb: dwc3: ep0: correct cache sync issue in case of ep0_bounced

[Greg Kroah-Hartman]

From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Pratyush Anand <pratyush.anand@xxxxxx>

commit 0416e494ce7dc84e2719bc9fb7daecb330476074 upstream.

In case of ep0 out, if length is not aligned to maxpacket size then we use
dwc->ep_bounce_addr for dma transfer and not request->dma. Since, we have
alreday done memcpy from dwc->ep0_bounce to request->buf, so we do not need to
issue cache sync function. In fact, cache sync function will bring wrong data
in request->buf from request->dma in this scenario.

So, cache sync function must not be executed in case of ep0 bounced.

Signed-off-by: Pratyush Anand <pratyush.anand@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/dwc3/ep0.c    |    1 -
 drivers/usb/dwc3/gadget.c |    7 +++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -702,7 +702,6 @@ static void dwc3_ep0_complete_data(struc
 		transferred = min_t(u32, ur->length,
 				transfer_size - length);
 		memcpy(ur->buf, dwc->ep0_bounce, transferred);
-		dwc->ep0_bounced = false;
 	} else {
 		transferred = ur->length - length;
 	}
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -238,8 +238,11 @@ void dwc3_gadget_giveback(struct dwc3_ep
 	if (req->request.status == -EINPROGRESS)
 		req->request.status = status;
 
-	usb_gadget_unmap_request(&dwc->gadget, &req->request,
-			req->direction);
+	if (dwc->ep0_bounced && dep->number == 0)
+		dwc->ep0_bounced = false;
+	else
+		usb_gadget_unmap_request(&dwc->gadget, &req->request,
+				req->direction);
 
 	dev_dbg(dwc->dev, "request %p from %s completed %d/%d ===> %d\n",
 			req, dep->name, req->request.actual,


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