Re: [PATCH 0/2] Disable SS instances in park mode for SC7180/ SC7280

[Konrad Dybcio]

On 30.05.2024 3:34 PM, Doug Anderson wrote:
> Hi,
> 
> On Thu, May 30, 2024 at 1:26 AM Krishna Kurapati
> <quic_kriskura@xxxxxxxxxxx> 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=/dev/sdb of=/dev/null
> bs=4M; 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=/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.

Right, this sounds like a more widespread issue

That said, I couldn't reproduce it on SC8280XP / X13s (which does NOT mean
8280 isn't affected). My setup was:

- USB3 5GB/s hub plugged into one of the side USBs
  - on-hub 1 Gb /s network hub connected straight to my router with a
    600 / 60 Mbps link, spamming speedtest-cli and dd-over-ssh
  - M.2 SSD connected over a USB adapter, nearing 280 MB/s speeds (the
    adapter isn't particularly speedy)

So it stands to reason that it might not have been enough to trigger it.

Konrad