From: Ramesh Babu ramesh.babu@intel.com

Add functions to set/get no-rewind flag

Signed-off-by: Ramesh Babu ramesh.babu@intel.com Signed-off-by: Sriram Periyasamy sriramx.periyasamy@intel.com ---

Please find the reference for previous discussion at [1].

[1] https://patchwork.kernel.org/patch/10191481/

include/pcm.h | 2 ++ include/sound/asound.h | 1 + src/pcm/pcm.c | 40 ++++++++++++++++++++++++++++++++++++++++ src/pcm/pcm_local.h | 1 + 4 files changed, 44 insertions(+)

diff --git a/include/pcm.h b/include/pcm.h index e2a53435caab..c6af884607ae 100644 --- a/include/pcm.h +++ b/include/pcm.h @@ -805,6 +805,8 @@ int snd_pcm_hw_params_set_export_buffer(snd_pcm_t *pcm, snd_pcm_hw_params_t *par int snd_pcm_hw_params_get_export_buffer(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val); int snd_pcm_hw_params_set_period_wakeup(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int val); int snd_pcm_hw_params_get_period_wakeup(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val); +int snd_pcm_hw_params_set_no_rewind(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int val); +int snd_pcm_hw_params_get_no_rewind(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val);

int snd_pcm_hw_params_get_period_time(const snd_pcm_hw_params_t *params, unsigned int *val, int *dir); int snd_pcm_hw_params_get_period_time_min(const snd_pcm_hw_params_t *params, unsigned int *val, int *dir); diff --git a/include/sound/asound.h b/include/sound/asound.h index 6041cab27a23..35fd50ec5395 100644 --- a/include/sound/asound.h +++ b/include/sound/asound.h @@ -375,6 +375,7 @@ typedef int snd_pcm_hw_param_t; #define SNDRV_PCM_HW_PARAMS_NORESAMPLE (1<<0) /* avoid rate resampling */ #define SNDRV_PCM_HW_PARAMS_EXPORT_BUFFER (1<<1) /* export buffer */ #define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2) /* disable period wakeups */ +#define SNDRV_PCM_HW_PARAMS_NO_REWINDS (1<<3) /* disable rewinds */

struct snd_interval { unsigned int min, max; diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index ed47cb516c73..3346609fdf6d 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -4826,6 +4826,46 @@ int snd_pcm_hw_params_get_period_wakeup(snd_pcm_t *pcm, snd_pcm_hw_params_t *par }

/** + * \brief Configure no-rewind flag through configuration space + * \param pcm PCM handle + * \param params Configuration space + * \param val 0 = disable (default), 1 = enable (default) no-rewind flag + * \return Zero on success, otherwise a negative error code. + * + * This function can be called to inform driver about application uses rewind or not + * + * Based on no-rewind flag, underlying driver could take decision on buffering scheme. + */ + +/* TODO: Invert the logic with function name set_rewind */ +int snd_pcm_hw_params_set_no_rewind(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int val) +{ + assert(pcm && params); + + if (val) { + params->flags |= SND_PCM_HW_PARAMS_NO_REWINDS; + } else + params->flags &= ~SND_PCM_HW_PARAMS_NO_REWINDS; + params->rmask = ~0; + + return snd_pcm_hw_refine(pcm, params); +} + +/** + * \brief Extract no-rewind flag from a configuration space + * \param pcm PCM handle + * \param params Configuration space + * \param val 0 = disabled, 1 = enabled no-rewind flag + * \return Zero on success, otherwise a negative error code. + */ +int snd_pcm_hw_params_get_no_rewind(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val) +{ + assert(pcm && params && val); + *val = params->flags & SND_PCM_HW_PARAMS_NO_REWINDS ? 0 : 1; + return 0; +} + +/** * \brief Extract period time from a configuration space * \param params Configuration space * \param val Returned approximate period duration in us diff --git a/src/pcm/pcm_local.h b/src/pcm/pcm_local.h index d52229d8ddea..2b3cae5b93f5 100644 --- a/src/pcm/pcm_local.h +++ b/src/pcm/pcm_local.h @@ -103,6 +103,7 @@ #define SND_PCM_HW_PARAMS_NORESAMPLE SNDRV_PCM_HW_PARAMS_NORESAMPLE #define SND_PCM_HW_PARAMS_EXPORT_BUFFER SNDRV_PCM_HW_PARAMS_EXPORT_BUFFER #define SND_PCM_HW_PARAMS_NO_PERIOD_WAKEUP SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP +#define SND_PCM_HW_PARAMS_NO_REWINDS SNDRV_PCM_HW_PARAMS_NO_REWINDS

#define SND_PCM_INFO_MONOTONIC 0x80000000