Re: [PATCH v9 26/34] ASoC: qcom: qdsp6: q6afe: Split USB AFE dev_token param into separate API

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> The Q6USB backend can carry information about the available USB SND cards
> and PCM devices discovered on the USB bus.  The dev_token field is used by
> the audio DSP to notify the USB offload driver of which card and PCM index
> to enable playback on.  Separate this into a dedicated API, so the USB
> backend can set the dev_token accordingly.  The audio DSP does not utilize
> this information until the AFE port start command is sent, which is done
> during the PCM prepare phase.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> ---
>  sound/soc/qcom/qdsp6/q6afe.c | 49 +++++++++++++++++++++++++-----------
>  sound/soc/qcom/qdsp6/q6afe.h |  1 +
>  2 files changed, 36 insertions(+), 14 deletions(-)
> 
> diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
> index 72c4e6fe20c4..f09a756246f8 100644
> --- a/sound/soc/qcom/qdsp6/q6afe.c
> +++ b/sound/soc/qcom/qdsp6/q6afe.c
> @@ -1394,10 +1394,42 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port,
>  }
>  EXPORT_SYMBOL_GPL(q6afe_tdm_port_prepare);
>  
> -static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +/**
> + * afe_port_send_usb_dev_param() - Send USB dev token
> + *
> + * @port: Instance of afe port
> + * @cardidx: USB SND card index to reference
> + * @pcmidx: USB SND PCM device index to reference
> + *
> + * The USB dev token carries information about which USB SND card instance and
> + * PCM device to execute the offload on.  This information is carried through
> + * to the stream enable QMI request, which is handled by the offload class
> + * driver.  The information is parsed to determine which USB device to query
> + * the required resources for.
> + */
> +int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx)
>  {
> -	union afe_port_config *pcfg = &port->port_cfg;
>  	struct afe_param_id_usb_audio_dev_params usb_dev;
> +	int ret;
> +
> +	memset(&usb_dev, 0, sizeof(usb_dev));
> +
> +	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> +	usb_dev.dev_token = (cardidx << 16) | (pcmidx << 8);
> +	ret = q6afe_port_set_param_v2(port, &usb_dev,
> +				AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> +				AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> +	if (ret)
> +		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> +			__func__, ret);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(afe_port_send_usb_dev_param);
> +
> +static int afe_port_send_usb_params(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +{
> +	union afe_port_config *pcfg = &port->port_cfg;
>  	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
>  	struct afe_param_id_usb_audio_svc_interval svc_int;
>  	int ret = 0;
> @@ -1408,20 +1440,9 @@ static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb
>  		goto exit;
>  	}
>  
> -	memset(&usb_dev, 0, sizeof(usb_dev));
>  	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
>  	memset(&svc_int, 0, sizeof(svc_int));
>  
> -	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> -	ret = q6afe_port_set_param_v2(port, &usb_dev,
> -				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> -				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> -	if (ret) {
> -		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> -			__func__, ret);
> -		goto exit;
> -	}
> -

this feels like a questionable patch split. Why not introduce the new
helper earlier and avoid adding code then modifying the same code?

>  	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>  	lpcm_fmt.endian = pcfg->usb_cfg.endian;
>  	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
> @@ -1463,7 +1484,7 @@ void q6afe_usb_port_prepare(struct q6afe_port *port,
>  	pcfg->usb_cfg.num_channels = cfg->num_channels;
>  	pcfg->usb_cfg.bit_width = cfg->bit_width;
>  
> -	afe_port_send_usb_dev_param(port, cfg);
> +	afe_port_send_usb_params(port, cfg);
>  }
>  EXPORT_SYMBOL_GPL(q6afe_usb_port_prepare);
>  
> diff --git a/sound/soc/qcom/qdsp6/q6afe.h b/sound/soc/qcom/qdsp6/q6afe.h
> index ef47b4ae9e27..2ce5ba9dba69 100644
> --- a/sound/soc/qcom/qdsp6/q6afe.h
> +++ b/sound/soc/qcom/qdsp6/q6afe.h
> @@ -263,6 +263,7 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port, struct q6afe_tdm_cfg *cfg);
>  void q6afe_cdc_dma_port_prepare(struct q6afe_port *port,
>  				struct q6afe_cdc_dma_cfg *cfg);
>  
> +int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx);
>  int q6afe_port_set_sysclk(struct q6afe_port *port, int clk_id,
>  			  int clk_src, int clk_root,
>  			  unsigned int freq, int dir);