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    SubjectRe: [PATCH v2 1/3] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue
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    On 15/12/2023 08:34, Chunfeng Yun wrote:
    > For Gen1 isoc-in endpoint on controller before about SSUSB IPM v1.6.0, it
    > still send out unexpected ACK after receiving a short packet in burst
    > transfer, this will cause an exception on connected device, specially for
    > a 4k camera.
    > Add a quirk property "rx-fifo-depth" to work around this hardware issue,
    > prefer to use 2;
    > The side-effect is that may cause performance drop about 10%, including
    > bulk transfer.
    >
    > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
    > ---
    > v2: change 'mediatek,rxfifo-depth' to 'rx-fifo-depth'
    > ---
    > .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml | 12 ++++++++++++
    > 1 file changed, 12 insertions(+)
    >
    > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
    > index e9644e333d78..e44a71acb5c0 100644
    > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
    > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
    > @@ -124,6 +124,18 @@ properties:
    > defined in the xHCI spec on MTK's controller.
    > default: 5000
    >
    > + rx-fifo-depth:
    > + $ref: /schemas/types.yaml#/definitions/uint32
    > + description:
    > + It is a quirk used to work around Gen1 isoc-in endpoint transfer issue
    > + that still send out unexpected ACK after device finish the burst transfer
    > + with a short packet and cause an exception, specially on a 4K camera
    > + device, it happens on controller before about IPM v1.6.0; the side-effect
    > + is that may cause performance drop about 10%, include bulk transfer,
    > + prefer to use 2 here.

    What is the meaning of 0-3? bytes? words?

    > + minimum: 0
    > + maximum: 3


    Best regards,
    Krzysztof


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