usb: musb: gadget: restart request on clearing endpoint halt

Commit 46034dca515bc4ddca0399ae58106d1f5f0d809f (USB: musb_gadget_ep0: stop
abusing musb_gadget_set_halt()) forgot to restart a queued request after
clearing the endpoint halt feature. This results in a couple of USB resets
while enumerating the file-backed storage gadget due to CSW packet not being
sent for the MODE SENSE(10) command.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: stable@kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 12 insertions, 1 deletions

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index cacae96468b9..d065e23f123e 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1084,7 +1084,7 @@ struct free_record {
 /*
  * Context: controller locked, IRQs blocked.
  */
-static void musb_ep_restart(struct musb *musb, struct musb_request *req)
+void musb_ep_restart(struct musb *musb, struct musb_request *req)
 {
         DBG(3, "<== %s request %p len %u on hw_ep%d\n",
                 req->tx ? "TX/IN" : "RX/OUT",
diff --git a/drivers/usb/musb/musb_gadget.h b/drivers/usb/musb/musb_gadget.h
index c8b140325d82..572b1da7f2dc 100644
--- a/drivers/usb/musb/musb_gadget.h
+++ b/drivers/usb/musb/musb_gadget.h
@@ -105,4 +105,6 @@ extern void musb_gadget_cleanup(struct musb *);
 
 extern void musb_g_giveback(struct musb_ep *, struct usb_request *, int);
 
+extern void musb_ep_restart(struct musb *, struct musb_request *);
+
 #endif          /* __MUSB_GADGET_H */
diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c
index 59bef8f3a358..6dd03f4c5f49 100644
--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -261,6 +261,7 @@ __acquires(musb->lock)
                                         ctrlrequest->wIndex & 0x0f;
                                 struct musb_ep          *musb_ep;
                                 struct musb_hw_ep       *ep;
+                                struct musb_request     *request;
                                 void __iomem            *regs;
                                 int                     is_in;
                                 u16                     csr;
@@ -302,6 +303,14 @@ __acquires(musb->lock)
                                         musb_writew(regs, MUSB_RXCSR, csr);
                                 }
 
+                                /* Maybe start the first request in the queue */
+                                request = to_musb_request(
+                                                next_request(musb_ep));
+                                if (!musb_ep->busy && request) {
+                                        DBG(3, "restarting the request\n");
+                                        musb_ep_restart(musb, request);
+                                }
+
                                 /* select ep0 again */
                                 musb_ep_select(mbase, 0);
                                 } break;