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

["Chunfeng Yun (云春峰)" <Chunfeng.Yun@mediatek.com>]

On Wed, 2023-12-13 at 09:05 +0100, Krzysztof Kozlowski wrote:
>  	 
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>  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@mediatek.com>
> > ---
> >  .../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.
I fix it as 2, it's OK to use a uint32, I'll modify it.

Thanks

> 
> 
> Best regards,
> Krzysztof
> 
>