[16/39] USB: musb: gadget_ep0: avoid SetupEnd interrupt

[Greg KH]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

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

From: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>

commit 17be5c5f5ef99c94374e07f71effa78e93a20eda upstream.

Gadget stalling a zero-length SETUP request results in this error message:

SetupEnd came in a wrong ep0stage idle

In order to avoid it, always set the CSR0.DataEnd bit after detecting a zero-
length request.  Add the missing '\n' to the error message itself as well...

Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Acked-by: Anand Gadiyar <gadiyar@xxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/musb/musb_gadget_ep0.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -646,7 +646,7 @@ irqreturn_t musb_g_ep0_irq(struct musb *
 			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 			break;
 		default:
-			ERR("SetupEnd came in a wrong ep0stage %s",
+			ERR("SetupEnd came in a wrong ep0stage %s\n",
 			    decode_ep0stage(musb->ep0_state));
 		}
 		csr = musb_readw(regs, MUSB_CSR0);
@@ -769,12 +769,18 @@ setup:
 				handled = service_zero_data_request(
 						musb, &setup);
 
+				/*
+				 * We're expecting no data in any case, so
+				 * always set the DATAEND bit -- doing this
+				 * here helps avoid SetupEnd interrupt coming
+				 * in the idle stage when we're stalling...
+				 */
+				musb->ackpend |= MUSB_CSR0_P_DATAEND;
+
 				/* status stage might be immediate */
-				if (handled > 0) {
-					musb->ackpend |= MUSB_CSR0_P_DATAEND;
+				if (handled > 0)
 					musb->ep0_state =
 						MUSB_EP0_STAGE_STATUSIN;
-				}
 				break;
 
 			/* sequence #1 (IN to host), includes GET_STATUS


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