usb: gadget: Fix race condition in connect/disconnect

This commit fixes race condition in fast connect/disconnect
of USB cable. This race condition can also be reproduced in
USB composition change. Thus this commit also adds support
for USB composition change for BAMtoBAM compositions.

CRs-fixed: 463705
Change-Id: I21abaff6a64bb405ce2d698605aff8e0050ef8d6
Signed-off-by: Anna Perel <aperel@codeaurora.org>
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>
diff --git a/drivers/usb/gadget/f_qc_rndis.c b/drivers/usb/gadget/f_qc_rndis.c
index 267cf53..c1ab552 100644
--- a/drivers/usb/gadget/f_qc_rndis.c
+++ b/drivers/usb/gadget/f_qc_rndis.c
@@ -725,14 +725,14 @@
 		 */
 		rndis->port.cdc_filter = 0;
 
+		if (rndis_qc_bam_connect(rndis))
+			goto fail;
+
 		DBG(cdev, "RNDIS RX/TX early activation ...\n");
 		net = gether_qc_connect_name(&rndis->port, "rndis0", false);
 		if (IS_ERR(net))
 			return PTR_ERR(net);
 
-		if (rndis_qc_bam_connect(rndis))
-			goto fail;
-
 		rndis_set_param_dev(rndis->config, net,
 				&rndis->port.cdc_filter);
 	} else
@@ -976,6 +976,8 @@
 {
 	struct f_rndis_qc		*rndis = func_to_rndis_qc(f);
 
+	pr_debug("rndis_qc_unbind: free");
+	bam_data_destroy(0);
 	rndis_deregister(rndis->config);
 	rndis_exit();