On Thu, Jan 12, 2023 at 6:59 AM Qun-Wei Lin <qun-wei.lin@xxxxxxxxxxxx> wrote:
>
> The "dma-ranges" property value is a sequence of
> child-address parent-address child-size
>
> The size of each field is determined by taking the child's
> "#address-cells" value, the parent's "#address-cells" value,
> and the child's "#size-cells" value.
>
> However, in the following example, it gives a false alarm:
> +-----------------------------------+---------------------------------------+
> | ranges.dts | dma-ranges.dts |
> +-----------------------------------+---------------------------------------+
> | /dts-v1/; | /dts-v1/; |
> | | |
> | /{ | /{ |
> | #address-cells = <1>; | #address-cells = <1>; |
> | | |
> | parent { | parent { |
> | #address-cells = <1>; | #address-cells = <1>; |
> | #size-cells = <1>; | #size-cells = <1>; |
> | ranges = <0x0 0xe000 0x1000>; | dma-ranges = <0x0 0xe000 0x1000>; |
> | child { | child { |
> | ... | ... |
> | }; | }; |
> | }; | }; |
> | }; | }; |
> +-----------------------------------+---------------------------------------+
> | no warning | Warning (avoid_unnecessary_addr_size) |
> +-----------------------------------+---------------------------------------+
>
> Same as "ranges", it should not be reported in this check.
Except that dma-ranges only makes sense if there is a ranges property.
Rob
