Re: [PATCH 08/10] ARM: dts: exynos: use proper 'dma-channels/requests' properties

From: Krzysztof Kozlowski
Date: Thu Apr 28 2022 - 06:15:25 EST


On 28/04/2022 12:05, Marek Szyprowski wrote:
>>>>> I also don't see any code that would read those properties. IMHO they
>>>>> should be simply removed at all, at least for the PL330 related nodes.
>>>> In current Linux implementation they indeed are not used. Nothing parses
>>>> them. However:
>>>> 1. They describe (hopefully correct) the hardware.
>>>> 2. They might be used by other implementations of pl330 driver.
>>>>
>>>> I would not remove them from existing sources, but indeed maybe there is
>>>> no need to add for new files.
>>> What's the point in having dt properties duplicating data that might be
>>> read from the driver registers?
>> Hm, indeed, there is no point in this. Since they are read from
>> registers, what was the idea behind in commit 42cf20980cde?
>
> #dma-cells is indeed required, but the rest seems to be the cargo-cult
> of some kind.

Rob,

Any guidance from your side? Is there any benefit in describing the
hadrware (dma-channels/dma-requests) if the same value can be read from
registers?


Best regards,
Krzysztof