Re: [RFC PATCH v2 11/22] ASoC: qcom: Add USB backend ASoC driver for Q6

[Srinivas Kandagatla]

On 26/01/2023 03:14, Wesley Cheng wrote:
> +}
> +
> +static int q6usb_dai_dev_probe(struct platform_device *pdev)
> +{
...
> +	data->priv.domain = iommu_domain_alloc(pdev->dev.bus);
> +	if (!data->priv.domain) {
> +		dev_err(&pdev->dev, "failed to allocate iommu domain\n");
> +		return -ENODEV;
> +	}
> +
> +	/* attach to external processor iommu */
> +	ret = iommu_attach_device(data->priv.domain, &pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to attach device ret = %d\n", ret);
> +		goto free_domain;
> +	}
> +
Why are we doing this manually here? device core should take care of 
attaching iommu to the device instance.

...


> +detach_device:
> +	iommu_detach_device(data->priv.domain, &pdev->dev);
> +free_domain:
> +	iommu_domain_free(data->priv.domain);
> +
> +	return ret;
> +}
> +
> +static int q6usb_dai_dev_remove(struct platform_device *pdev)
> +{
> +	struct q6usb_port_data *data = platform_get_drvdata(pdev);
> +
> +	iommu_detach_device(data->priv.domain, &pdev->dev);
> +	iommu_domain_free(data->priv.domain);
> +