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Message-ID: <1718f25d-3274-3e4d-0cdf-72fda8788e39@linux.intel.com>
Date: Thu, 28 Dec 2023 12:44:15 +0200
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To: Chunfeng Yun <chunfeng.yun@mediatek.com>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
 Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Conor Dooley <conor+dt@kernel.org>,
 Matthias Brugger <matthias.bgg@gmail.com>,
 Mathias Nyman <mathias.nyman@intel.com>, linux-usb@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org,
 devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
 Eddie Hung <eddie.hung@mediatek.com>, Macpaul Lin <macpaul.lin@mediatek.com>
References: <20231227060316.8539-1-chunfeng.yun@mediatek.com>
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Subject: Re: [PATCH v4 1/3] dt-bindings: usb: mtk-xhci: add a property for
 Gen1 isoc-in transfer issue
In-Reply-To: <20231227060316.8539-1-chunfeng.yun@mediatek.com>
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Hi

On 27.12.2023 8.03, 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 3k bytes;
> The side-effect is that may cause performance drop about 10%, including
> bulk transfer.

Is it be possible to detect those Mediatek xHC versions that need this
workaround in the xhci-mtk driver directly?

This way we could avoid passing a new "rx-fifo-depth" property to it.

Thanks
Mathias