diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index ce9e31f3d26bc..6b929defc2d25 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -31,6 +31,12 @@ #include #include +#include /* for USB_GADGET_DELAYED_STATUS */ + +/* Undef helpers from linux/usb/composite.h as gadgetfs redefines them */ +#undef DBG +#undef ERROR +#undef INFO /* @@ -1511,7 +1517,16 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) event->u.setup = *ctrl; ep0_readable (dev); spin_unlock (&dev->lock); - return 0; + /* + * Return USB_GADGET_DELAYED_STATUS as a workaround to + * stop some UDC drivers (e.g. dwc3) from automatically + * proceeding with the status stage for 0-length + * transfers. + * Should be removed once all UDC drivers are fixed to + * always delay the status stage until a response is + * queued to EP0. + */ + return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0; } }