On Wed, 2023-12-20 at 08:25 +0100, Krzysztof Kozlowski wrote: > > External email : Please do not click links or open attachments until > you have verified the sender or the content. > On 20/12/2023 03:05, Chunfeng Yun (云春峰) wrote: > > 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 > > No, don't add. Just use correct values. 0 means 0 words or bytes. Not > 1000 bytes. Ok, I'll modify it; Thanks > > Best regards, > Krzysztof >
