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SubjectRe: [PATCH] soundwire: debugfs: use controller id instead of link_id
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>>>> link_id can be zero and if we have multiple controller instances
>>>> in a system like Qualcomm debugfs will end-up with duplicate namespace
>>>> resulting in incorrect debugfs entries.
>>>>
>>>> Using id should give a unique debugfs directory entry and should fix
>>>> below
>>>> warning too.
>>>> "debugfs: Directory 'master-0' with parent 'soundwire' already
>>>> present!"
>>>
>>> Yeah id is guaranteed to be unique so this will work.
>>>
>>> Applied, thanks
>>
>> This patch is a no-op for Intel, but I am not convinced it's the right
>> fix or the definitions are not consistent.
>
> It depends if the intention is to represent full Hierarchy in debugfs,
> then I agree. Its was consistent even before!

Indeed, we don't currently have a notion of controller in debugfs.

> currently we have
> /sys/kernel/debug/soundwire/master-*
>
> Are you suggesting that we have something like this:
>
> /sys/kernel/debug/soundwire/xyz-controller/master-<LINK-ID> ??

Yes this is what I was thinking about.

> /sys/kernel/debug/soundwire/xyz-controller/master-<LINK-ID>/xyz-slave/master-<LINK-ID>
> ??

This would be for a bridge which to the best of my knowledge hasn't been
implemented by anyone (clocking and command/control timing issues).

> Or may be something much simpler like:
>
> /sys/kernel/debug/soundwire/master-<ID>.<LINK_ID>

the bus->id is an IDA, which is useful for to avoid conflicts, but it's
not really meaningful for debugfs. I remember seeing a case where we had
links 2 and 4 enabled, and the bus->id were 0 and 1, a completely
artificial value that doesn't really help in debugging.

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