Re: [PATCH] ASoC: SOF: Use flexible allocation for control data

["Péter Ujfalusi" <peter.ujfalusi@linux.intel.com>]

On 19/05/2026 03:47, Rosen Penev wrote:
> Allocate IPC3 and IPC4 channel control data with kzalloc_flex()
> for the trailing channel-value arrays instead of open-coding the
> struct_size() allocation.
> 
> The existing scontrol size field continues to record the payload size
> used by the control paths.
> 
> Assisted-by: Codex:GPT-5.5
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>  sound/soc/sof/ipc3-topology.c | 6 ++++--
>  sound/soc/sof/ipc4-topology.c | 6 ++++--
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/sound/soc/sof/ipc3-topology.c b/sound/soc/sof/ipc3-topology.c
> index 8c37c0657315..9597f619fbe4 100644
> --- a/sound/soc/sof/ipc3-topology.c
> +++ b/sound/soc/sof/ipc3-topology.c
> @@ -1826,7 +1826,8 @@ static int sof_ipc3_control_load_volume(struct snd_sof_dev *sdev, struct snd_sof
>  	/* init the volume get/put data */
>  	scontrol->size = struct_size(cdata, chanv, scontrol->num_channels);
>  
> -	scontrol->ipc_control_data = kzalloc(scontrol->size, GFP_KERNEL);
> +	scontrol->ipc_control_data = kzalloc_flex(*cdata, chanv,
> +						  scontrol->num_channels);

I don't think this helps at all.
We need to calculate the size anyways, so it is better to use that, no
need to do double calculation.

>  	if (!scontrol->ipc_control_data)
>  		return -ENOMEM;
>  
> @@ -1857,7 +1858,8 @@ static int sof_ipc3_control_load_enum(struct snd_sof_dev *sdev, struct snd_sof_c
>  	/* init the enum get/put data */
>  	scontrol->size = struct_size(cdata, chanv, scontrol->num_channels);
>  
> -	scontrol->ipc_control_data = kzalloc(scontrol->size, GFP_KERNEL);
> +	scontrol->ipc_control_data = kzalloc_flex(*cdata, chanv,
> +						  scontrol->num_channels);
>  	if (!scontrol->ipc_control_data)
>  		return -ENOMEM;
>  
> diff --git a/sound/soc/sof/ipc4-topology.c b/sound/soc/sof/ipc4-topology.c
> index 76812d8fb567..9fd04a7857f6 100644
> --- a/sound/soc/sof/ipc4-topology.c
> +++ b/sound/soc/sof/ipc4-topology.c
> @@ -2863,7 +2863,8 @@ static int sof_ipc4_control_load_volume(struct snd_sof_dev *sdev, struct snd_sof
>  	scontrol->size = struct_size(control_data, chanv, scontrol->num_channels);
>  
>  	/* scontrol->ipc_control_data will be freed in sof_control_unload */
> -	scontrol->ipc_control_data = kzalloc(scontrol->size, GFP_KERNEL);
> +	scontrol->ipc_control_data = kzalloc_flex(*control_data, chanv,
> +						  scontrol->num_channels);
>  	if (!scontrol->ipc_control_data)
>  		return -ENOMEM;
>  
> @@ -2905,7 +2906,8 @@ static int sof_ipc4_control_load_enum(struct snd_sof_dev *sdev, struct snd_sof_c
>  	scontrol->size = struct_size(control_data, chanv, scontrol->num_channels);
>  
>  	/* scontrol->ipc_control_data will be freed in sof_control_unload */
> -	scontrol->ipc_control_data = kzalloc(scontrol->size, GFP_KERNEL);
> +	scontrol->ipc_control_data = kzalloc_flex(*control_data, chanv,
> +						  scontrol->num_channels);
>  	if (!scontrol->ipc_control_data)
>  		return -ENOMEM;
>  

-- 
Péter