USB: musb: gadget_ep0: avoid SetupEnd interrupt

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@ru.mvista.com>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c
index 8fba3f11e473..53d06451f820 100644
--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -664,7 +664,7 @@ irqreturn_t musb_g_ep0_irq(struct musb *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);
@@ -787,12 +787,18 @@ 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