Re: [PATCH 01/13] ALSA: pcm: add more sample rate definitions

[Pierre-Louis Bossart]

On 9/5/24 16:12, Jerome Brunet wrote:
> This adds a sample rate definition for 12kHz, 24kHz and 128kHz.
> 
> Admittedly, just a few drivers are currently using these sample
> rates but there is enough of a recurrence to justify adding a definition
> for them and remove some custom rate constraint code while at it.
> 
> The new definitions are not added to the interval definitions, such as
> SNDRV_PCM_RATE_8000_44100, because it would silently add new supported
> rates to drivers that may or may not support them. For sure the drivers
> have not been tested for these new rates so it is better to leave them out
> of interval definitions.
> 
> That being said, the added rates are multiples of well know rates families,
> it is very likely that a lot of devices out there actually supports them.
> 
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
>  include/sound/pcm.h     | 31 +++++++++++++++++--------------
>  sound/core/pcm_native.c |  6 +++---
>  2 files changed, 20 insertions(+), 17 deletions(-)
> 
> diff --git a/include/sound/pcm.h b/include/sound/pcm.h
> index 732121b934fd..c993350975a9 100644
> --- a/include/sound/pcm.h
> +++ b/include/sound/pcm.h
> @@ -109,20 +109,23 @@ struct snd_pcm_ops {
>  #define SNDRV_PCM_RATE_5512		(1U<<0)		/* 5512Hz */
>  #define SNDRV_PCM_RATE_8000		(1U<<1)		/* 8000Hz */
>  #define SNDRV_PCM_RATE_11025		(1U<<2)		/* 11025Hz */
> -#define SNDRV_PCM_RATE_16000		(1U<<3)		/* 16000Hz */
> -#define SNDRV_PCM_RATE_22050		(1U<<4)		/* 22050Hz */
> -#define SNDRV_PCM_RATE_32000		(1U<<5)		/* 32000Hz */
> -#define SNDRV_PCM_RATE_44100		(1U<<6)		/* 44100Hz */
> -#define SNDRV_PCM_RATE_48000		(1U<<7)		/* 48000Hz */
> -#define SNDRV_PCM_RATE_64000		(1U<<8)		/* 64000Hz */
> -#define SNDRV_PCM_RATE_88200		(1U<<9)		/* 88200Hz */
> -#define SNDRV_PCM_RATE_96000		(1U<<10)	/* 96000Hz */
> -#define SNDRV_PCM_RATE_176400		(1U<<11)	/* 176400Hz */
> -#define SNDRV_PCM_RATE_192000		(1U<<12)	/* 192000Hz */
> -#define SNDRV_PCM_RATE_352800		(1U<<13)	/* 352800Hz */
> -#define SNDRV_PCM_RATE_384000		(1U<<14)	/* 384000Hz */
> -#define SNDRV_PCM_RATE_705600		(1U<<15)	/* 705600Hz */
> -#define SNDRV_PCM_RATE_768000		(1U<<16)	/* 768000Hz */
> +#define SNDRV_PCM_RATE_12000		(1U<<3)		/* 12000Hz */
> +#define SNDRV_PCM_RATE_16000		(1U<<4)		/* 16000Hz */
> +#define SNDRV_PCM_RATE_22050		(1U<<5)		/* 22050Hz */
> +#define SNDRV_PCM_RATE_24000		(1U<<6)		/* 24000Hz */
> +#define SNDRV_PCM_RATE_32000		(1U<<7)		/* 32000Hz */
> +#define SNDRV_PCM_RATE_44100		(1U<<8)		/* 44100Hz */
> +#define SNDRV_PCM_RATE_48000		(1U<<9)		/* 48000Hz */
> +#define SNDRV_PCM_RATE_64000		(1U<<10)	/* 64000Hz */
> +#define SNDRV_PCM_RATE_88200		(1U<<11)	/* 88200Hz */
> +#define SNDRV_PCM_RATE_96000		(1U<<12)	/* 96000Hz */
> +#define SNDRV_PCM_RATE_128000		(1U<<13)	/* 128000Hz */
> +#define SNDRV_PCM_RATE_176400		(1U<<14)	/* 176400Hz */
> +#define SNDRV_PCM_RATE_192000		(1U<<15)	/* 192000Hz */
> +#define SNDRV_PCM_RATE_352800		(1U<<16)	/* 352800Hz */
> +#define SNDRV_PCM_RATE_384000		(1U<<17)	/* 384000Hz */
> +#define SNDRV_PCM_RATE_705600		(1U<<18)	/* 705600Hz */
> +#define SNDRV_PCM_RATE_768000		(1U<<19)	/* 768000Hz */
>  
>  #define SNDRV_PCM_RATE_CONTINUOUS	(1U<<30)	/* continuous range */
>  #define SNDRV_PCM_RATE_KNOT		(1U<<31)	/* supports more non-continuous rates */
> diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
> index 44381514f695..7461a727615c 100644
> --- a/sound/core/pcm_native.c
> +++ b/sound/core/pcm_native.c
> @@ -2418,13 +2418,13 @@ static int snd_pcm_hw_rule_sample_bits(struct snd_pcm_hw_params *params,
>  	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
>  }
>  
> -#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
> +#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_768000 != 1 << 19
>  #error "Change this table"
>  #endif
>  
>  static const unsigned int rates[] = {
> -	5512, 8000, 11025, 16000, 22050, 32000, 44100,
> -	48000, 64000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000
> +	5512, 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000, 64000,
> +	88200, 96000, 128000, 176400, 192000, 352800, 384000, 705600, 768000,
>  };
>  
>  const struct snd_pcm_hw_constraint_list snd_pcm_known_rates = {

Wondering if this is backwards compatible with the alsa-lib definitions,
specifically the topology parts which did unfortunately have a list of
rates that will map to a different index now:


typedef enum _snd_pcm_rates {
	SND_PCM_RATE_UNKNOWN = -1,
	SND_PCM_RATE_5512 = 0,
	SND_PCM_RATE_8000,
	SND_PCM_RATE_11025,
	SND_PCM_RATE_16000,
	SND_PCM_RATE_22050,
	SND_PCM_RATE_32000,
	SND_PCM_RATE_44100,
	SND_PCM_RATE_48000,
	SND_PCM_RATE_64000,
	SND_PCM_RATE_88200,
	SND_PCM_RATE_96000,
	SND_PCM_RATE_176400,
	SND_PCM_RATE_192000,
	SND_PCM_RATE_CONTINUOUS = 30,
	SND_PCM_RATE_KNOT = 31,
	SND_PCM_RATE_LAST = SND_PCM_RATE_KNOT,
} snd_pcm_rates_t;