From 223b4ef5a3b75c4500facf07f99a925232eaf113 Mon Sep 17 00:00:00 2001 From: Chunfeng Yun Date: Thu, 4 Jan 2024 14:16:38 +0800 Subject: [PATCH] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue 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 3k bytes; The side-effect is that it may cause performance drop about 10%, including bulk transfer. Acked-by: Krzysztof Kozlowski Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Chunfeng Yun Link: https://lore.kernel.org/r/20240104061640.7335-1-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman --- .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml index e9644e333d78..924fd3d748a8 100644 --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml @@ -124,6 +124,17 @@ 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 finishes 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 it may cause performance drop about 10%, + including bulk transfer, prefer to use 3k here. The size is in bytes. + enum: [1024, 2048, 3072, 4096] + # the following properties are only used for case 1 wakeup-source: description: enable USB remote wakeup, see power/wakeup-source.txt -- 2.25.1