[PATCH 05/10] ALSA: aloop: Use callback functions for timer specific implementations

twischer
2019-03-26T07:50:06Z

From: Timo Wischer <twischer@de.adit-jv.com>

This commit only refectors the implementation. It does not change the
behaviour.
It is required to support other timers (e.g sound timer).

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
---
sound/drivers/aloop.c | 113 +++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 94 insertions(+), 19 deletions(-)

diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index c6217c4..422d130 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -69,8 +69,39 @@ MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels change

#define NO_PITCH 100000

+struct loopback_cable;
struct loopback_pcm;

+struct loopback_ops {
+ /* optional
+ * call in loopback->cable_lock
+ */
+ int (*open)(struct loopback_pcm *dpcm);
+ /* required
+ * call in cable->lock
+ */
+ int (*start)(struct loopback_pcm *dpcm);
+ /* required
+ * call in cable->lock
+ */
+ int (*stop)(struct loopback_pcm *dpcm);
+ /* optional */
+ int (*stop_sync)(struct loopback_pcm *dpcm);
+ /* optional */
+ int (*close_substream)(struct loopback_pcm *dpcm);
+ /* optional
+ * call in loopback->cable_lock
+ */
+ int (*close_cable)(struct loopback_pcm *dpcm);
+ /* optional
+ * call in cable->lock
+ */
+ unsigned int (*pos_update)(struct loopback_cable *cable);
+ /* optional */
+ void (*dpcm_info)(struct loopback_pcm *dpcm,
+ struct snd_info_buffer *buffer);
+};
+
struct loopback_cable {
spinlock_t lock;
struct loopback_pcm *streams[2];
@@ -79,6 +110,8 @@ struct loopback_cable {
unsigned int valid;
unsigned int running;
unsigned int pause;
+ /* timer specific */
+ struct loopback_ops *ops;
};

struct loopback_setup {
@@ -285,7 +318,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
spin_lock_irqsave(&cable->lock, flags);
cable->running |= stream;
cable->pause &= ~stream;
- err = loopback_timer_start(dpcm);
+ err = cable->ops->start(dpcm);
spin_unlock_irqrestore(&cable->lock, flags);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
loopback_active_notify(dpcm);
@@ -294,7 +327,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
spin_lock_irqsave(&cable->lock, flags);
cable->running &= ~stream;
cable->pause &= ~stream;
- err = loopback_timer_stop(dpcm);
+ err = cable->ops->stop(dpcm);
spin_unlock_irqrestore(&cable->lock, flags);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
loopback_active_notify(dpcm);
@@ -303,7 +336,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
case SNDRV_PCM_TRIGGER_SUSPEND:
spin_lock_irqsave(&cable->lock, flags);
cable->pause |= stream;
- err = loopback_timer_stop(dpcm);
+ err = cable->ops->stop(dpcm);
spin_unlock_irqrestore(&cable->lock, flags);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
loopback_active_notify(dpcm);
@@ -313,7 +346,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
spin_lock_irqsave(&cable->lock, flags);
dpcm->last_jiffies = jiffies;
cable->pause &= ~stream;
- err = loopback_timer_start(dpcm);
+ err = cable->ops->start(dpcm);
spin_unlock_irqrestore(&cable->lock, flags);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
loopback_active_notify(dpcm);
@@ -344,9 +377,11 @@ static int loopback_prepare(struct snd_pcm_substream *substream)
struct loopback_cable *cable = dpcm->cable;
int err, bps, salign;

- err = loopback_timer_stop_sync(dpcm);
- if (err < 0)
- return err;
+ if (cable->ops->stop_sync) {
+ err = cable->ops->stop_sync(dpcm);
+ if (err < 0)
+ return err;
+ }

salign = (snd_pcm_format_width(runtime->format) *
runtime->channels) / 8;
@@ -554,6 +589,18 @@ static void loopback_timer_function(struct timer_list *t)
spin_unlock_irqrestore(&dpcm->cable->lock, flags);
}

+static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm,
+ struct snd_info_buffer *buffer)
+{
+ snd_iprintf(buffer, " update_pending:\t%u\n",
+ dpcm->period_update_pending);
+ snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
+ snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
+ snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
+ dpcm->last_jiffies, jiffies);
+ snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
+}
+
static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
@@ -562,7 +609,8 @@ static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
snd_pcm_uframes_t pos;

spin_lock_irqsave(&dpcm->cable->lock, flags);
- loopback_pos_update(dpcm->cable);
+ if (dpcm->cable->ops->pos_update)
+ dpcm->cable->ops->pos_update(dpcm->cable);
pos = dpcm->buf_pos;
spin_unlock_irqrestore(&dpcm->cable->lock, flags);
return bytes_to_frames(runtime, pos);
@@ -688,12 +736,33 @@ static void free_cable(struct snd_pcm_substream *substream)
cable->streams[substream->stream] = NULL;
spin_unlock_irqrestore(&cable->lock, flags);
} else {
+ struct loopback_pcm *dpcm = substream->runtime->private_data;
+
+ if (cable->ops && cable->ops->close_cable && dpcm)
+ cable->ops->close_cable(dpcm);
/* free the cable */
loopback->cables[substream->number][dev] = NULL;
kfree(cable);
}
}

+static int loopback_jiffies_timer_open(struct loopback_pcm *dpcm)
+{
+ timer_setup(&dpcm->timer, loopback_timer_function, 0);
+
+ return 0;
+}
+
+static struct loopback_ops loopback_jiffies_timer_ops = {
+ .open = loopback_jiffies_timer_open,
+ .start = loopback_timer_start,
+ .stop = loopback_timer_stop,
+ .stop_sync = loopback_timer_stop_sync,
+ .close_substream = loopback_timer_stop_sync,
+ .pos_update = loopback_pos_update,
+ .dpcm_info = loopback_jiffies_timer_dpcm_info,
+};
+
static int loopback_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
@@ -712,7 +781,6 @@ static int loopback_open(struct snd_pcm_substream *substream)
}
dpcm->loopback = loopback;
dpcm->substream = substream;
- timer_setup(&dpcm->timer, loopback_timer_function, 0);

cable = loopback->cables[substream->number][dev];
if (!cable) {
@@ -723,9 +791,17 @@ static int loopback_open(struct snd_pcm_substream *substream)
}
spin_lock_init(&cable->lock);
cable->hw = loopback_pcm_hardware;
+ cable->ops = &loopback_jiffies_timer_ops;
loopback->cables[substream->number][dev] = cable;
}
dpcm->cable = cable;
+ runtime->private_data = dpcm;
+
+ if (cable->ops->open) {
+ err = cable->ops->open(dpcm);
+ if (err < 0)
+ goto unlock;
+ }

snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);

@@ -751,7 +827,9 @@ static int loopback_open(struct snd_pcm_substream *substream)
if (err < 0)
goto unlock;

- runtime->private_data = dpcm;
+ /* loopback_runtime_free() has not to be called if kfree(dpcm) was
+ * already called here. Otherwise it will end up with a double free.
+ */
runtime->private_free = loopback_runtime_free;
if (get_notify(dpcm))
runtime->hw = loopback_pcm_hardware;
@@ -775,12 +853,14 @@ static int loopback_close(struct snd_pcm_substream *substream)
{
struct loopback *loopback = substream->private_data;
struct loopback_pcm *dpcm = substream->runtime->private_data;
+ int err = 0;

- loopback_timer_stop_sync(dpcm);
+ if (dpcm->cable->ops->close_substream)
+ err = dpcm->cable->ops->close_substream(dpcm);
mutex_lock(&loopback->cable_lock);
free_cable(substream);
mutex_unlock(&loopback->cable_lock);
- return 0;
+ return err;
}

static const struct snd_pcm_ops loopback_pcm_ops = {
@@ -1103,13 +1183,8 @@ static void print_dpcm_info(struct snd_info_buffer *buffer,
snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
- snd_iprintf(buffer, " update_pending:\t%u\n",
- dpcm->period_update_pending);
- snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
- snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
- snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
- dpcm->last_jiffies, jiffies);
- snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
+ if (dpcm->cable->ops->dpcm_info)
+ dpcm->cable->ops->dpcm_info(dpcm, buffer);
}

static void print_substream_info(struct snd_info_buffer *buffer,
--
2.7.4