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Diffstat (limited to 'sound/usb')
-rw-r--r--sound/usb/card.h2
-rw-r--r--sound/usb/endpoint.c42
2 files changed, 29 insertions, 15 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 37091b117614..a741e7da83a2 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -71,7 +71,7 @@ struct snd_usb_endpoint {
unsigned char altsetting; /* corresponding alternate setting */
unsigned char ep_idx; /* endpoint array index */
- unsigned long flags; /* running bit flags */
+ atomic_t state; /* running state */
void (*prepare_data_urb) (struct snd_usb_substream *subs,
struct urb *urb);
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index e102c024c21f..4390075b2c6f 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -21,8 +21,11 @@
#include "clock.h"
#include "quirks.h"
-#define EP_FLAG_RUNNING 1
-#define EP_FLAG_STOPPING 2
+enum {
+ EP_STATE_STOPPED,
+ EP_STATE_RUNNING,
+ EP_STATE_STOPPING,
+};
/* interface refcounting */
struct snd_usb_iface_ref {
@@ -115,6 +118,16 @@ static const char *usb_error_string(int err)
}
}
+static inline bool ep_state_running(struct snd_usb_endpoint *ep)
+{
+ return atomic_read(&ep->state) == EP_STATE_RUNNING;
+}
+
+static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)
+{
+ return atomic_cmpxchg(&ep->state, old, new) == old;
+}
+
/**
* snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
*
@@ -393,7 +406,7 @@ next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)
*/
static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
{
- while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
+ while (ep_state_running(ep)) {
unsigned long flags;
struct snd_usb_packet_info *packet;
@@ -454,13 +467,13 @@ static void snd_complete_urb(struct urb *urb)
if (unlikely(atomic_read(&ep->chip->shutdown)))
goto exit_clear;
- if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+ if (unlikely(!ep_state_running(ep)))
goto exit_clear;
if (usb_pipeout(ep->pipe)) {
retire_outbound_urb(ep, ctx);
/* can be stopped during retire callback */
- if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+ if (unlikely(!ep_state_running(ep)))
goto exit_clear;
if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
@@ -474,12 +487,12 @@ static void snd_complete_urb(struct urb *urb)
prepare_outbound_urb(ep, ctx);
/* can be stopped during prepare callback */
- if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+ if (unlikely(!ep_state_running(ep)))
goto exit_clear;
} else {
retire_inbound_urb(ep, ctx);
/* can be stopped during retire callback */
- if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+ if (unlikely(!ep_state_running(ep)))
goto exit_clear;
prepare_inbound_urb(ep, ctx);
@@ -835,7 +848,7 @@ static int wait_clear_urbs(struct snd_usb_endpoint *ep)
unsigned long end_time = jiffies + msecs_to_jiffies(1000);
int alive;
- if (!test_bit(EP_FLAG_STOPPING, &ep->flags))
+ if (atomic_read(&ep->state) != EP_STATE_STOPPING)
return 0;
do {
@@ -850,10 +863,11 @@ static int wait_clear_urbs(struct snd_usb_endpoint *ep)
usb_audio_err(ep->chip,
"timeout: still %d active urbs on EP #%x\n",
alive, ep->ep_num);
- clear_bit(EP_FLAG_STOPPING, &ep->flags);
- ep->sync_sink = NULL;
- snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
+ if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
+ ep->sync_sink = NULL;
+ snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
+ }
return 0;
}
@@ -882,10 +896,9 @@ static int stop_urbs(struct snd_usb_endpoint *ep, bool force)
if (!force && atomic_read(&ep->running))
return -EBUSY;
- if (!test_and_clear_bit(EP_FLAG_RUNNING, &ep->flags))
+ if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
return 0;
- set_bit(EP_FLAG_STOPPING, &ep->flags);
INIT_LIST_HEAD(&ep->ready_playback_urbs);
ep->next_packet_head = 0;
ep->next_packet_queued = 0;
@@ -1362,7 +1375,8 @@ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
* from that context.
*/
- set_bit(EP_FLAG_RUNNING, &ep->flags);
+ if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))
+ goto __error;
if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
for (i = 0; i < ep->nurbs; i++) {