On Fri, 2023-12-15 at 08:36 +0100, Krzysztof Kozlowski wrote: > > External email : Please do not click links or open attachments until > you have verified the sender or the content. > 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@xxxxxxxxxxxx> > > --- > > 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? 0 - 1K bytes; 3 - 4K bytes; I will add this in description > > > + minimum: 0 > > + maximum: 3 > > > Best regards, > Krzysztof > >
