Re: [PATCH v2 1/2] ASoC: tegra210_adx: simplify byte map get/put logic

[Jon Hunter <jonathanh@nvidia.com>]

On 08/04/2026 18:08, Piyush Patle wrote:
> The byte-map controls ("Byte Map N") already expose a value range of
> [0, 256] to userspace via SOC_SINGLE_EXT(), where 256 is the
> "disabled" sentinel. The driver stored this state as a byte-packed
> u32 map[] array plus a separate byte_mask[] bitmap tracking which
> slots were enabled, because 256 does not fit in a byte. As a result
> get_byte_map() had to consult byte_mask[] to decide whether to
> report the stored byte or 256, and put_byte_map() had to keep the
> two arrays in sync on every write.
> 
> Store each slot as a u16 holding the control value directly
> (0..255 enabled, 256 disabled). This is the native representation
> for what userspace already sees, so get_byte_map() becomes a direct
> return and put_byte_map() becomes a compare-and-store. The
> hardware-facing packed RAM word and the IN_BYTE_EN mask are now
> derived on the fly inside tegra210_adx_write_map_ram() from the
> slot array, which is the only place that needs to know about the
> hardware layout.
> 
> The byte_mask scratch buffer is allocated dynamically using
> kcalloc() based on soc_data->byte_mask_size, removing dependency
> on SoC-specific constants. The byte_mask field is dropped from
> struct tegra210_adx.

So this was already the case. However ...


> -static void tegra210_adx_write_map_ram(struct tegra210_adx *adx)
> +static int tegra210_adx_write_map_ram(struct tegra210_adx *adx)
>   {
> +	const unsigned int bits_per_mask = BITS_PER_TYPE(*adx->map) * BITS_PER_BYTE;
> +	unsigned int *byte_mask;
>   	int i;
>   
> +	byte_mask = kcalloc(adx->soc_data->byte_mask_size, sizeof(*byte_mask),
> +			    GFP_KERNEL);
> +	if (!byte_mask)
> +		return -ENOMEM;
> +

Now you are allocating this everytime this function is called (which 
happens on RPM resume) instead of ...

> @@ -700,16 +706,15 @@ static int tegra210_adx_platform_probe(struct platform_device *pdev)
>   
>   	regcache_cache_only(adx->regmap, true);
>   
> -	adx->map = devm_kzalloc(dev, soc_data->ram_depth * sizeof(*adx->map),
> -				GFP_KERNEL);
> +	adx->map = devm_kcalloc(dev,
> +				soc_data->ram_depth * TEGRA_ADX_SLOTS_PER_WORD,
> +				sizeof(*adx->map), GFP_KERNEL);
>   	if (!adx->map)
>   		return -ENOMEM;
>   
> -	adx->byte_mask = devm_kzalloc(dev,
> -				      soc_data->byte_mask_size * sizeof(*adx->byte_mask),
> -				      GFP_KERNEL);
> -	if (!adx->byte_mask)
> -		return -ENOMEM;

... here in the probe function, which makes more sense. IOW I am not 
sure why you have changed this.

Jon

-- 
nvpublic