usb: dwc3: gadget: Delay issuing End Transfer

If the controller hasn't DMA'ed the Setup data from its fifo, it won't
process the End Transfer command. Polling for the command completion may
block the driver from servicing the Setup phase and cause a timeout.
Previously we only check and delay issuing End Transfer in the case of
endpoint dequeue. Let's do that for all End Transfer scenarios.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/2fcf3b5d90068d549589a57a27a79f76c6769b04.1650593829.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 4f445f8..4f54f0e 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2062,16 +2062,6 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
                if (r == req) {
                        struct dwc3_request *t;
 
-                       /*
-                        * If a Setup packet is received but yet to DMA out, the controller will
-                        * not process the End Transfer command of any endpoint. Polling of its
-                        * DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
-                        * timeout. Delay issuing the End Transfer command until the Setup TRB is
-                        * prepared.
-                        */
-                       if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status)
-                               dep->flags |= DWC3_EP_DELAY_STOP;
-
                        /* wait until it is processed */
                        dwc3_stop_active_transfer(dep, true, true);
 
@@ -3702,6 +3692,18 @@ void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
                return;
 
        /*
+        * If a Setup packet is received but yet to DMA out, the controller will
+        * not process the End Transfer command of any endpoint. Polling of its
+        * DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
+        * timeout. Delay issuing the End Transfer command until the Setup TRB is
+        * prepared.
+        */
+       if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status) {
+               dep->flags |= DWC3_EP_DELAY_STOP;
+               return;
+       }
+
+       /*
         * NOTICE: We are violating what the Databook says about the
         * EndTransfer command. Ideally we would _always_ wait for the
         * EndTransfer Command Completion IRQ, but that's causing too