@@ -397,7 +397,7 @@ struct snd_pcm_runtime {
snd_pcm_uframes_t silence_start; /* starting pointer to silence area */
snd_pcm_uframes_t silence_filled; /* already filled part of silence area */
- unsigned char sync[16]; /* hardware synchronization ID */
+ bool sync_flag; /* hardware synchronization - standard per card ID */
/* -- mmap -- */
struct snd_pcm_mmap_status *status;
@@ -1151,7 +1151,19 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int
void snd_pcm_set_ops(struct snd_pcm * pcm, int direction,
const struct snd_pcm_ops *ops);
-void snd_pcm_set_sync(struct snd_pcm_substream *substream);
+void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params,
+ const unsigned char *id, unsigned int len);
+/**
+ * snd_pcm_set_sync - set the PCM sync id
+ * snd_pcm_set_sync_per_card - set the PCM sync id with card number
+ * @substream: the pcm substream
+ *
+ * Use the default PCM sync identifier for the specific card.
+ */
+static inline void snd_pcm_set_sync(struct snd_pcm_substream *substream)
+{
+ substream->runtime->sync_flag = true;
+}
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
unsigned int cmd, void *arg);
void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream);
@@ -5,7 +5,6 @@
* Abramo Bagnara <abramo@alsa-project.org>
*/
-#include <asm/unaligned.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/time.h>
@@ -517,19 +516,37 @@ void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
EXPORT_SYMBOL(snd_pcm_set_ops);
/**
- * snd_pcm_set_sync - set the PCM sync id
+ * snd_pcm_set_sync_per_card - set the PCM sync id with card number
* @substream: the pcm substream
+ * @params: modified hardware parameters
+ * @id: identifier (max 12 bytes)
+ * @len: identifier length (max 12 bytes)
*
- * Sets the PCM sync identifier for the card.
+ * Sets the PCM sync identifier for the card with zero padding.
+ *
+ * User space or any user should use this 16-byte identifier for a comparison only
+ * to check if two IDs are similar or different. Special case is the identifier
+ * containing only zeros. Interpretation for this combination is - empty (not set).
+ * The contents of the identifier should not be interpreted in any other way.
+ *
+ * The synchronization ID must be unique per clock source (usually one sound card,
+ * but multiple soundcard may use one PCM word clock source which means that they
+ * are fully synchronized).
+ *
+ * This routine composes this ID using card number in first four bytes and
+ * 12-byte additional ID. When other ID composition is used (e.g. for multiple
+ * sound cards), make sure that the composition does not clash with this
+ * composition scheme.
*/
-void snd_pcm_set_sync(struct snd_pcm_substream *substream)
+void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ const unsigned char *id, unsigned int len)
{
- struct snd_pcm_runtime *runtime = substream->runtime;
-
- *(__u32 *)runtime->sync = cpu_to_le32(substream->pcm->card->number);
- memset(runtime->sync + 4, 0xff, sizeof(runtime->sync) - 4);
+ *(__u32 *)params->sync = cpu_to_le32(substream->pcm->card->number);
+ len = max(12, len);
+ strncpy(params->sync + 4, id, len);
+ memset(params->sync + 4 + len, 0, 12 - len);
}
-EXPORT_SYMBOL(snd_pcm_set_sync);
/*
* Standard ioctl routine
@@ -1809,21 +1826,15 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
return 0;
}
-/**
- * is sync id (clock id) empty?
- */
-static inline bool pcm_sync_empty(const unsigned char *sync)
-{
- return get_unaligned((__u64 *)(sync + 0)) == 0 && get_unaligned((__u64 *)(sync + 8)) == 0;
-}
-
static int snd_pcm_lib_ioctl_sync_id(struct snd_pcm_substream *substream,
void *arg)
{
- struct snd_pcm_hw_params *params = arg;
+ static const unsigned char id[12] = { 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff };
- if (pcm_sync_empty(params->sync))
- memcpy(params->sync, substream->runtime->sync, sizeof(params->sync));
+ if (substream->runtime->sync_flag)
+ snd_pcm_set_sync_per_card(substream, arg, id, sizeof(id));
return 0;
}
@@ -174,10 +174,6 @@ static int snd_p16v_pcm_open_playback_channel(struct snd_pcm_substream *substrea
if (err < 0)
return err;
- *(__u32 *)runtime->sync = cpu_to_le32(substream->pcm->card->number);
- memset(runtime->sync + 4, 0, sizeof(runtime->sync) - 4);
- strncpy(runtime->sync + 4, "P16V", 4);
-
return 0;
}
@@ -225,6 +221,17 @@ static int snd_p16v_pcm_open_capture(struct snd_pcm_substream *substream)
return snd_p16v_pcm_open_capture_channel(substream, 0);
}
+static int snd_p16v_pcm_ioctl_playback(struct snd_pcm_substream *substream,
+ unsigned int cmd, void *arg)
+{
+ if (cmd == SNDRV_PCM_IOCTL1_SYNC_ID) {
+ static const unsigned char id[4] = { 'P', '1', '6', 'V' };
+ snd_pcm_set_sync_per_card(substream, arg, id, 4);
+ return 0;
+ }
+ return snd_pcm_lib_ioctl(substream, cmd, arg);
+}
+
/* prepare playback callback */
static int snd_p16v_pcm_prepare_playback(struct snd_pcm_substream *substream)
{
@@ -530,6 +537,7 @@ snd_p16v_pcm_pointer_capture(struct snd_pcm_substream *substream)
static const struct snd_pcm_ops snd_p16v_playback_front_ops = {
.open = snd_p16v_pcm_open_playback_front,
.close = snd_p16v_pcm_close_playback,
+ .ioctl = snd_p16v_pcm_ioctl_playback,
.prepare = snd_p16v_pcm_prepare_playback,
.trigger = snd_p16v_pcm_trigger_playback,
.pointer = snd_p16v_pcm_pointer_playback,
Optimize the memory usage in struct snd_pcm_runtime - use boolean value for the standard sync ID scheme. Introduce snd_pcm_set_sync_per_card function to build synchronization IDs. Signed-off-by: Jaroslav Kysela <perex@perex.cz> --- include/sound/pcm.h | 16 +++++++++++-- sound/core/pcm_lib.c | 51 ++++++++++++++++++++++++---------------- sound/pci/emu10k1/p16v.c | 16 +++++++++---- 3 files changed, 57 insertions(+), 26 deletions(-)