usb: gadget: f_rndis: OS Descriptors configfs support

Added handling of OS Descriptors support for f_rndis.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_rndis.c

@@ -27,6 +27,7 @@
 #include "u_ether_configfs.h"
 #include "u_rndis.h"
 #include "rndis.h"
+#include "configfs.h"
 
 /*
  * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
@@ -895,12 +896,15 @@ static void rndis_free_inst(struct usb_function_instance *f)
 		else
 			free_netdev(opts->net);
 	}
+
+	kfree(opts->rndis_os_desc.group.default_groups); /* single VLA chunk */
 	kfree(opts);
 }
 
 static struct usb_function_instance *rndis_alloc_inst(void)
 {
 	struct f_rndis_opts *opts;
+	struct usb_os_desc *descs[1];
 
 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 	if (!opts)
@@ -917,6 +921,9 @@ static struct usb_function_instance *rndis_alloc_inst(void)
 	}
 	INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
 
+	descs[0] = &opts->rndis_os_desc;
+	usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
+				       THIS_MODULE);
 	config_group_init_type_name(&opts->func_inst.group, "",
 				    &rndis_func_type);