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authorJanusz Dziedzic <januszx.dziedzic@intel.com>2017-03-13 14:11:32 +0200
committerFelipe Balbi <felipe.balbi@linux.intel.com>2017-03-22 11:20:36 +0200
commitde288e36fe33f7e06fa272bc8e2f85aa386d99aa (patch)
tree852db978a33b3518b4e4a74b977fc75da3ead2a6 /drivers/usb
parent97da3854c526d3a6ee05c849c96e48d21527606c (diff)
usb: dwc3: gadget: delay unmap of bounced requests
In the case of bounced ep0 requests, we must delay DMA operation until after ->complete() otherwise we might overwrite contents of req->buf. This caused problems with RNDIS gadget. Signed-off-by: Janusz Dziedzic <januszx.dziedzic@intel.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/dwc3/gadget.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0d75158e43fe..79e7a3480d51 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -171,6 +171,7 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
int status)
{
struct dwc3 *dwc = dep->dwc;
+ unsigned int unmap_after_complete = false;
req->started = false;
list_del(&req->list);
@@ -180,11 +181,19 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
if (req->request.status == -EINPROGRESS)
req->request.status = status;
- if (dwc->ep0_bounced && dep->number <= 1)
+ /*
+ * NOTICE we don't want to unmap before calling ->complete() if we're
+ * dealing with a bounced ep0 request. If we unmap it here, we would end
+ * up overwritting the contents of req->buf and this could confuse the
+ * gadget driver.
+ */
+ if (dwc->ep0_bounced && dep->number <= 1) {
dwc->ep0_bounced = false;
-
- usb_gadget_unmap_request_by_dev(dwc->sysdev,
- &req->request, req->direction);
+ unmap_after_complete = true;
+ } else {
+ usb_gadget_unmap_request_by_dev(dwc->sysdev,
+ &req->request, req->direction);
+ }
trace_dwc3_gadget_giveback(req);
@@ -192,6 +201,10 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
usb_gadget_giveback_request(&dep->endpoint, &req->request);
spin_lock(&dwc->lock);
+ if (unmap_after_complete)
+ usb_gadget_unmap_request_by_dev(dwc->sysdev,
+ &req->request, req->direction);
+
if (dep->number > 1)
pm_runtime_put(dwc->dev);
}