[PATCH v3 1/5] iommu: Return -EMEDIUMTYPE for incompatible domain and device/group

[Baolu Lu]

On 2022/6/24 04:00, Nicolin Chen wrote:
> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
> index e1cb51b9866c..5386d889429d 100644
> --- a/drivers/iommu/mtk_iommu_v1.c
> +++ b/drivers/iommu/mtk_iommu_v1.c
> @@ -304,7 +304,7 @@ static int mtk_iommu_v1_attach_device(struct iommu_domain *domain, struct device
>   	/* Only allow the domain created internally. */
>   	mtk_mapping = data->mapping;
>   	if (mtk_mapping->domain != domain)
> -		return 0;
> +		return -EMEDIUMTYPE;
>   
>   	if (!data->m4u_dom) {
>   		data->m4u_dom = dom;

This change looks odd. It turns the return value from success to
failure. Is it a bug? If so, it should go through a separated fix patch.

Best regards,
baolu