Re: [PATCH] arm64: dts: qcom: sm8450: delete incorrect ufs interconnect fields

From: Jonathan Marek
Date: Thu Apr 07 2022 - 18:38:54 EST


On 4/7/22 5:16 PM, Krzysztof Kozlowski wrote:
On 07/04/2022 21:40, Vladimir Zapolskiy wrote:
On 4/7/22 20:21, Jonathan Marek wrote:
Upstream sm8450.dtsi has #interconnect-cells = <2>; so these are wrong.
Ignored and undocumented with upstream UFS driver so delete for now.

This is the upstream and they are documented here, although as pointed
by Vladimir this was rather a reverse-documentation. The documentation
might be incorrect, but then the bindings should be corrected instead of
only modifying the DTS.


Basically the description was added by a commit 462c5c0aa798 ("dt-bindings: ufs:
qcom,ufs: convert to dtschema").

It's questionable, if an example in the new yaml file is totally correct
in connection to the discussed issue.

To be honest - the example probably is not correct, because it was based
on existing DTS without your patch. :)

Another question is whether the interconnect properties are here correct
at all. I assumed that DTS is correct because it should describe the
hardware, even if driver does not use it. However maybe that was a false
assumption...


writing-bindings.rst says it is OK to document even if it isn't used by the driver (seems wrong to me, at least for interconnects which are a firmware abstraction and not hardware).

462c5c0aa798 wasn't in my 5.17+ tree pulled after dts changes were merged (I guess doc changes come later), so my commit message is incorrect, but I think it makes more sense to have the documentation reflect the driver. Its also not an important issue, so I'll let others sort it out.


Best regards,
Krzysztof