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path: root/drivers/usb
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-rw-r--r--drivers/usb/gadget/function/f_midi.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 84c0ee5ebd1e..56e2dde99b03 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 */];
@@ -597,17 +599,22 @@ 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)
goto drop_out;
} while (ret);
+ spin_unlock_irqrestore(&midi->transmit_lock, flags);
+
return;
drop_out:
@@ -1201,6 +1208,8 @@ 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);