diff options
| -rw-r--r-- | sound/usb/card.h | 2 | ||||
| -rw-r--r-- | sound/usb/endpoint.c | 42 |
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++) { |