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    SubjectRe: [PATCH 2/3] ASoC: dt-bindings: sama7g5-pdmc: add microchip,startup-delay-us binding
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    On 16/02/2023 11:15, Claudiu.Beznea@microchip.com wrote:
    > On 16.02.2023 12:04, Krzysztof Kozlowski wrote:
    >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
    >>
    >> On 14/02/2023 17:14, Claudiu Beznea wrote:
    >>> Add microchip,startup-delay-us binding to let PDMC users to specify
    >>> startup delay.
    >>>
    >>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
    >>> ---
    >>> .../devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml | 6 ++++++
    >>> 1 file changed, 6 insertions(+)
    >>>
    >>> diff --git a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml
    >>> index c4cf1e5ab84b..9b40268537cb 100644
    >>> --- a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml
    >>> +++ b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml
    >>> @@ -67,6 +67,12 @@ properties:
    >>> maxItems: 4
    >>> uniqueItems: true
    >>>
    >>> + microchip,startup-delay-us:
    >>> + description: |
    >>> + Specifies the delay in microseconds that needs to be applied after
    >>> + enabling the PDMC microphones to avoid unwanted noise due to microphones
    >>> + not being ready.
    >>
    >> Is this some hardware delay? Or OS? If OS, why Linux specific delay is
    >> put into DT?
    >
    > It's the delay used in software workaround that IP needs to filter noises.

    Then this sounds like OS? Linux related properties usually do not belong
    to DT.

    > The IP is not fully featured to do this kind of filtering on its own thus
    > this software workaround. This delay may depend on used microphones thus
    > for different kind of setups (PDMC + different microphones) I introduced
    > this in DT.

    I understand your driver needs delay and I am not questioning this. I am
    questioning why this is suitable for DT?


    Best regards,
    Krzysztof

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