summaryrefslogtreecommitdiff
path: root/sound/usb
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2021-08-30 08:04:04 +0200
committerTakashi Iwai <tiwai@suse.de>2021-08-30 08:04:04 +0200
commitf7b82b12626e10a2f5332b699cc79819ac8decc7 (patch)
treee530e0ebd7c60c9f466fdc00e809c024e63c664a /sound/usb
parentea41a498cc646349d64eda7e8a4e23ae999bc259 (diff)
parent4801bee7d5a36c199b734a28cde5259183aff822 (diff)
Merge branch 'for-linus' into for-next
Diffstat (limited to 'sound/usb')
-rw-r--r--sound/usb/card.c4
-rw-r--r--sound/usb/card.h2
-rw-r--r--sound/usb/endpoint.c4
-rw-r--r--sound/usb/pcm.c14
-rw-r--r--sound/usb/usbaudio.h1
5 files changed, 23 insertions, 2 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c
index cf8f3953f78f..fd570a42f043 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -68,6 +68,7 @@ static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
static bool ignore_ctl_error;
static bool autoclock = true;
+static bool lowlatency = true;
static char *quirk_alias[SNDRV_CARDS];
static char *delayed_register[SNDRV_CARDS];
static bool implicit_fb[SNDRV_CARDS];
@@ -93,6 +94,8 @@ MODULE_PARM_DESC(ignore_ctl_error,
"Ignore errors from USB controller for mixer interfaces.");
module_param(autoclock, bool, 0444);
MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
+module_param(lowlatency, bool, 0444);
+MODULE_PARM_DESC(lowlatency, "Enable low latency playback (default: yes).");
module_param_array(quirk_alias, charp, NULL, 0444);
MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
module_param_array(delayed_register, charp, NULL, 0444);
@@ -623,6 +626,7 @@ static int snd_usb_audio_create(struct usb_interface *intf,
chip->setup = device_setup[idx];
chip->generic_implicit_fb = implicit_fb[idx];
chip->autoclock = autoclock;
+ chip->lowlatency = lowlatency;
atomic_set(&chip->active, 1); /* avoid autopm during probing */
atomic_set(&chip->usage_count, 0);
atomic_set(&chip->shutdown, 0);
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 6c0a052a28f9..5b19901f305a 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -94,6 +94,7 @@ struct snd_usb_endpoint {
struct list_head ready_playback_urbs; /* playback URB FIFO for implicit fb */
unsigned int nurbs; /* # urbs */
+ unsigned int nominal_queue_size; /* total buffer sizes in URBs */
unsigned long active_mask; /* bitmask of active urbs */
unsigned long unlink_mask; /* bitmask of unlinked urbs */
char *syncbuf; /* sync buffer for all sync URBs */
@@ -187,6 +188,7 @@ struct snd_usb_substream {
} dsd_dop;
bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
+ bool early_playback_start; /* early start needed for playback? */
struct media_ctl *media_ctl;
};
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 79a8c569c62b..533919a28856 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1132,6 +1132,10 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep)
INIT_LIST_HEAD(&u->ready_list);
}
+ /* total buffer bytes of all URBs plus the next queue;
+ * referred in pcm.c
+ */
+ ep->nominal_queue_size = maxsize * urb_packs * (ep->nurbs + 1);
return 0;
out_of_memory:
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 4e5031a68064..5dc9266180e3 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -614,6 +614,15 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
subs->period_elapsed_pending = 0;
runtime->delay = 0;
+ /* check whether early start is needed for playback stream */
+ subs->early_playback_start =
+ subs->direction == SNDRV_PCM_STREAM_PLAYBACK &&
+ (!chip->lowlatency ||
+ (subs->data_endpoint->nominal_queue_size >= subs->buffer_bytes));
+
+ if (subs->early_playback_start)
+ ret = start_endpoints(subs);
+
unlock:
snd_usb_unlock_shutdown(chip);
return ret;
@@ -1394,7 +1403,7 @@ static void prepare_playback_urb(struct snd_usb_substream *subs,
subs->trigger_tstamp_pending_update = false;
}
- if (period_elapsed && !subs->running) {
+ if (period_elapsed && !subs->running && !subs->early_playback_start) {
subs->period_elapsed_pending = 1;
period_elapsed = 0;
}
@@ -1448,7 +1457,8 @@ static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substrea
prepare_playback_urb,
retire_playback_urb,
subs);
- if (cmd == SNDRV_PCM_TRIGGER_START) {
+ if (!subs->early_playback_start &&
+ cmd == SNDRV_PCM_TRIGGER_START) {
err = start_endpoints(subs);
if (err < 0) {
snd_usb_endpoint_set_callback(subs->data_endpoint,
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 94261d19cceb..167834133b9b 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -55,6 +55,7 @@ struct snd_usb_audio {
bool generic_implicit_fb; /* from the 'implicit_fb' module param */
bool autoclock; /* from the 'autoclock' module param */
+ bool lowlatency; /* from the 'lowlatency' module param */
struct usb_host_interface *ctrl_intf; /* the audio control interface */
struct media_device *media_dev;
struct media_intf_devnode *ctl_intf_media_devnode;