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

[Chunfeng Yun (云春峰)]

On Wed, 2023-12-13 at 12:17 +0100, AngeloGioacchino Del Regno wrote:
> 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.
Yes, only for RX

> 
> Cheers,
> Angelo
> 
>