[alsa-devel] [PATCH] ASoC: Add accessor macros for TLV items

[Takashi Iwai]

On Tue, 27 Mar 2018 20:39:45 +0200,
Ranjani Sridharan wrote:
> 
> This patch adds macros for accessing the type, length, min, mute
> and step items in TLV data. These will be used by drivers to extract
> the TLV data while loading topology.
> 
> Signed-off-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>

The subject is wrongly prefixed.  This is ALSA core API stuff, not
about ASoC.

And about the change...

> --- a/include/sound/tlv.h
> +++ b/include/sound/tlv.h
> @@ -49,6 +49,11 @@
>  
>  #define TLV_DB_GAIN_MUTE		SNDRV_CTL_TLVD_DB_GAIN_MUTE
>  
> +#define TLV_ITEM_TYPE			SNDRV_CTL_TLVD_ITEM_TYPE
> +#define TLV_ITEM_LEN			SNDRV_CTL_TLVD_ITEM_LEN
> +#define TLV_DB_MIN			SNDRV_CTL_TLVD_DB_SCALE_MIN
> +#define TLV_DB_MUTE_AND_STEP		SNDRV_CTL_TLVD_DB_SCALE_MUTE_AND_STEP

What's the reason of these redundant redefinitions?


> --- a/include/uapi/sound/tlv.h
> +++ b/include/uapi/sound/tlv.h
> @@ -60,6 +60,13 @@
>  	unsigned int name[] = { \
>  		SNDRV_CTL_TLVD_DB_SCALE_ITEM(min, step, mute) \
>  	}
> +/* Accessor macros for TLV type and len */
> +#define SNDRV_CTL_TLVD_ITEM_TYPE		0
> +#define SNDRV_CTL_TLVD_ITEM_LEN			1
> +
> +/* Accessor macros for min, mute and step values from dB scale type TLV */
> +#define SNDRV_CTL_TLVD_DB_SCALE_MIN		2
> +#define SNDRV_CTL_TLVD_DB_SCALE_MUTE_AND_STEP	3

These are no "macros" but constants.  And, they use the same prefix
SNDRV_CTL_TLVD_* as other existing macros.  SNDTV_CTL_TLVD_*() is a
macro to define/expand a TLV descriptor.  It's not for defining the
offset value as added in the patch.

That is, better to choose another unique prefix to distinguish the
definitions clearly.


thanks,

Takashi