[PATCH 1/2] ASoC: soc-ops: Fix clamp range for SOC_DOUBLE_SX_TLV controls

[PATCH 1/2] ASoC: soc-ops: Fix clamp range for SOC_DOUBLE_SX_TLV controls

[Cole Leavitt]

For SOC_DOUBLE_SX_TLV controls, mc->min represents the hardware register
offset (e.g., 283) and mc->max represents the number of user-visible
steps (e.g., 229). The valid hardware register range is therefore
[min, min + max], not [min, max].

When min > max (which is valid for SX controls), the clamp() call
misbehaves because it expects min <= max. This causes the control
read function to return incorrect values.

For example, with the CS42L43 headphone volume control:
  - min = 0x11B (283), max = 229
  - Register value 0x1FF (511) should read as user value 228
  - But clamp(511, 283, 229) returns 229, then 229 - 283 = -54
  - The masked result (-54 & 0x1FF) = 458, which is wrong

Fix by clamping to [min, min + max] which correctly handles both
regular controls (where min=0) and SX controls (where min is an offset).

Signed-off-by: Cole Leavitt <cole@unwrap.rs>
---
 sound/soc/soc-ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/soc-ops.c b/sound/soc/soc-ops.c
index ce86978c1..b28fdf238 100644
--- a/sound/soc/soc-ops.c
+++ b/sound/soc/soc-ops.c
@@ -148,7 +148,7 @@ static int soc_mixer_reg_to_ctl(struct soc_mixer_control *mc, unsigned int reg_v
 	if (mc->sign_bit)
 		val = sign_extend32(val, mc->sign_bit);
 
-	val = clamp(val, mc->min, mc->max);
+	val = clamp(val, mc->min, mc->min + mc->max);
 	val -= mc->min;
 
 	if (mc->invert)
-- 
2.52.0

Re: [PATCH 1/2] ASoC: soc-ops: Fix clamp range for SOC_DOUBLE_SX_TLV controls

[Charles Keepax]

On Sun, Jan 11, 2026 at 08:13:29PM -0700, Cole Leavitt wrote:
> For SOC_DOUBLE_SX_TLV controls, mc->min represents the hardware register
> offset (e.g., 283) and mc->max represents the number of user-visible
> steps (e.g., 229). The valid hardware register range is therefore
> [min, min + max], not [min, max].
> 
> When min > max (which is valid for SX controls), the clamp() call
> misbehaves because it expects min <= max. This causes the control
> read function to return incorrect values.
> 
> For example, with the CS42L43 headphone volume control:
>   - min = 0x11B (283), max = 229
>   - Register value 0x1FF (511) should read as user value 228
>   - But clamp(511, 283, 229) returns 229, then 229 - 283 = -54
>   - The masked result (-54 & 0x1FF) = 458, which is wrong
> 
> Fix by clamping to [min, min + max] which correctly handles both
> regular controls (where min=0) and SX controls (where min is an offset).
> 
> Signed-off-by: Cole Leavitt <cole@unwrap.rs>
> ---
>  sound/soc/soc-ops.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/soc-ops.c b/sound/soc/soc-ops.c
> index ce86978c1..b28fdf238 100644
> --- a/sound/soc/soc-ops.c
> +++ b/sound/soc/soc-ops.c
> @@ -148,7 +148,7 @@ static int soc_mixer_reg_to_ctl(struct soc_mixer_control *mc, unsigned int reg_v
>  	if (mc->sign_bit)
>  		val = sign_extend32(val, mc->sign_bit);
>  
> -	val = clamp(val, mc->min, mc->max);
> +	val = clamp(val, mc->min, mc->min + mc->max);

No, this was discussed here:

https://lore.kernel.org/linux-sound/20251217120623.16620-1-peter.ujfalusi@linux.intel.com/

And the actual fix was merged here:

https://lore.kernel.org/all/20251216134938.788625-1-sbinding@opensource.cirrus.com/

Thanks,
Charles