usb: dwc3: ep0: correct cache sync issue in case of ep0_bounced

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.

Cc: <stable@vger.kernel.org> # v3.4 v3.5
Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 5 insertions, 3 deletions

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 9b94886b66e5..e4d5ca86b9da 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -720,7 +720,6 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
                 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;
         }
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 58fdfad96b4d..c99568eb4292 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -263,8 +263,11 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
         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,