[PATCH] USB: gadget zero poisons OUT buffers

Fill OUT buffers with 0x55 before RX, so that controller driver
bugs that mangle data can be more readily detected during testing.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c
index 51424f66a765..68e3d8f5da89 100644
--- a/drivers/usb/gadget/zero.c
+++ b/drivers/usb/gadget/zero.c
@@ -572,9 +572,10 @@ static void source_sink_complete (struct usb_ep *ep, struct usb_request *req)
         switch (status) {
 
         case 0:                         /* normal completion? */
-                if (ep == dev->out_ep)
+                if (ep == dev->out_ep) {
                         check_read_data (dev, ep, req);
-                else
+                        memset (req->buf, 0x55, req->length);
+                } else
                         reinit_write_data (dev, ep, req);
                 break;
 
@@ -626,6 +627,8 @@ source_sink_start_ep (struct usb_ep *ep, gfp_t gfp_flags)
 
         if (strcmp (ep->name, EP_IN_NAME) == 0)
                 reinit_write_data (ep->driver_data, ep, req);
+        else
+                memset (req->buf, 0x55, req->length);
 
         status = usb_ep_queue (ep, req, gfp_flags);
         if (status) {