1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 84c0ee5ebd1e..58fc199a18ec 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/kfifo.h>
+#include <linux/spinlock.h>
 
 #include <sound/core.h>
 #include <sound/initval.h>
@@ -89,6 +90,7 @@ struct f_midi {
         unsigned int buflen, qlen;
         /* This fifo is used as a buffer ring for pre-allocated IN usb_requests */
         DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *);
+        spinlock_t transmit_lock;
         unsigned int in_last_port;
 
         struct gmidi_in_port    in_ports_array[/* in_ports */];
@@ -358,7 +360,9 @@ static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
         /* allocate a bunch of read buffers and queue them all at once. */
         for (i = 0; i < midi->qlen && err == 0; i++) {
                 struct usb_request *req =
-                        midi_alloc_ep_req(midi->out_ep, midi->buflen);
+                        midi_alloc_ep_req(midi->out_ep,
+                                max_t(unsigned, midi->buflen,
+                                        bulk_out_desc.wMaxPacketSize));
                 if (req == NULL)
                         return -ENOMEM;
 
@@ -597,17 +601,24 @@ static void f_midi_transmit(struct f_midi *midi)
 {
         struct usb_ep *ep = midi->in_ep;
         int ret;
+        unsigned long flags;
 
         /* We only care about USB requests if IN endpoint is enabled */
         if (!ep || !ep->enabled)
                 goto drop_out;
 
+        spin_lock_irqsave(&midi->transmit_lock, flags);
+
         do {
                 ret = f_midi_do_transmit(midi, ep);
-                if (ret < 0)
+                if (ret < 0) {
+                        spin_unlock_irqrestore(&midi->transmit_lock, flags);
                         goto drop_out;
+                }
         } while (ret);
 
+        spin_unlock_irqrestore(&midi->transmit_lock, flags);
+
         return;
 
 drop_out:
@@ -1201,6 +1212,8 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
         if (status)
                 goto setup_fail;
 
+        spin_lock_init(&midi->transmit_lock);
+
         ++opts->refcnt;
         mutex_unlock(&opts->lock);