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From: Doug Anderson <dianders@chromium.org>
Date: Thu, 30 May 2024 06:34:28 -0700
Message-ID: <CAD=FV=UhrCKCv5R-LAAugrLXFp=cDcj2=Pp9-N3qk5pk2=sGEg@mail.gmail.com>
Subject: Re: [PATCH 0/2] Disable SS instances in park mode for SC7180/ SC7280
To: Krishna Kurapati <quic_kriskura@quicinc.com>
Cc: cros-qcom-dts-watchers@chromium.org, 
	Krzysztof Kozlowski <krzk+dt@kernel.org>, Rob Herring <robh@kernel.org>, 
	Bjorn Andersson <andersson@kernel.org>, Konrad Dybcio <konrad.dybcio@linaro.org>, 
	Conor Dooley <conor+dt@kernel.org>, Stephen Boyd <swboyd@chromium.org>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Matthias Kaehlcke <mka@chromium.org>, 
	linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, 
	devicetree@vger.kernel.org, quic_ppratap@quicinc.com, quic_jackp@quicinc.com
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Hi,

On Thu, May 30, 2024 at 1:26=E2=80=AFAM Krishna Kurapati
<quic_kriskura@quicinc.com> wrote:
>
> When working in host mode, in certain conditions, when the USB
> host controller is stressed, there is a HC died warning that comes up.
> Fix this up by disabling SS instances in park mode for SC7280 and SC7180.
>
> Krishna Kurapati (2):
>   arm64: dts: qcom: sc7180: Disable SS instances in park mode
>   arm64: dts: qcom: sc7280: Disable SS instances in park mode
>
>  arch/arm64/boot/dts/qcom/sc7180.dtsi | 1 +
>  arch/arm64/boot/dts/qcom/sc7280.dtsi | 1 +
>  2 files changed, 2 insertions(+)

FWIW, the test case I used to reproduce this:

1. Plug in a USB dock w/ Ethernet
2. Plug a USB 3 SD card reader into the dock.
3. Use lsusb -t to confirm both Ethernet and card reader are on USB3.
4. From a shell, run for i in $(seq 5); do dd if=3D/dev/sdb of=3D/dev/null
bs=3D4M; done to read from the card reader.
5. At the same time, stress the Internet. If you've got a very fast
Internet connection then running Google's "Internet speed test" did
it, but I could also reproduce by just running this from a PC
connected to the same network as my DUT: ssh ${DUT} "dd of=3D/dev/null"
< /dev/zero

I would also note that, though I personally reproduced this on sc7180
and sc7280 boards and thus Krishna posted the patch for those boards,
there's no reason to believe that this problem doesn't affect all of
Qualcomm's SoCs. It would be nice if someone at Qualcomm could post a
followup patch fixing this everywhere.

-Doug