1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 89179ab20c10..7ee057930ae7 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -113,6 +113,7 @@ struct gs_port {
         int write_allocated;
         struct gs_buf           port_write_buf;
         wait_queue_head_t       drain_wait;     /* wait while writes drain */
+        bool                    write_busy;
 
         /* REVISIT this state ... */
         struct usb_cdc_line_coding port_line_coding;    /* 8-N-1 etc */
@@ -363,7 +364,7 @@ __acquires(&port->port_lock)
         int                     status = 0;
         bool                    do_tty_wake = false;
 
-        while (!list_empty(pool)) {
+        while (!port->write_busy && !list_empty(pool)) {
                 struct usb_request      *req;
                 int                     len;
 
@@ -393,9 +394,11 @@ __acquires(&port->port_lock)
                  * NOTE that we may keep sending data for a while after
                  * the TTY closed (dev->ioport->port_tty is NULL).
                  */
+                port->write_busy = true;
                 spin_unlock(&port->port_lock);
                 status = usb_ep_queue(in, req, GFP_ATOMIC);
                 spin_lock(&port->port_lock);
+                port->write_busy = false;
 
                 if (status) {
                         pr_debug("%s: %s %s err %d\n",