Re: [PATCH 1/3] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue

[AngeloGioacchino Del Regno]

Il 13/12/23 09:05, Krzysztof Kozlowski ha scritto:
> On 13/12/2023 07:35, 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 "mediatek,rxfifo-depth" to work around this hardware
> > issue;
> > The side-effect is that may cause performance drop about 10%, including
> > bulk transfer.
> >
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml     | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > index e9644e333d78..b8ed68574ba4 100644
> > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > @@ -124,6 +124,16 @@ properties:
> >         defined in the xHCI spec on MTK's controller.
> >       default: 5000
> >   
> > +  mediatek,rxfifo-depth:
> > +    description:
>
> The property description and driver patch suggest you configure the
> depth of FIFO, so this should be not bool, but some uint32. And then,
> use generic "fifo-depth" property to set desired depth.

Did you mean "rx-fifo-depth" instead, as used in net?
This FIFO depth parameter is for RX only.

Cheers,
Angelo