Re: [PATCH stable-5.15 3/3] usb: dwc3: disable USB core PHY management

Marek Szyprowski
2022-10-28T13:48:21Z

Dear All,

On 18.10.2022 17:27, Stefan Agner wrote:
> Hi Johan,
>
> On 2022-09-06 14:07, Johan Hovold wrote:
>> From: Johan Hovold <johan+linaro@kernel.org>
>>
>> commit 6000b8d900cd5f52fbcd0776d0cc396e88c8c2ea upstream.
>>
>> The dwc3 driver manages its PHYs itself so the USB core PHY management
>> needs to be disabled.
>>
>> Use the struct xhci_plat_priv hack added by commits 46034a999c07 ("usb:
>> host: xhci-plat: add platform data support") and f768e718911e ("usb:
>> host: xhci-plat: add priv quirk for skip PHY initialization") to
>> propagate the setting for now.
> [adding also Samsung/ODROID device tree authors Krzysztof and Marek]
>
> For some reason, this commit seems to break detection of the USB to
> S-ATA controller on ODROID-HC1 devices (Exynos 5422).
>
> We have a known to work OS release of v5.15.60, and known to not be
> working of v5.15.67. By reverting suspicious commits, I was able to
> pinpoint the problem to this particular commit.
>
> >From what I understand, on that particular hardware the S-ATA controller
> power is controlled via the V-BUS signal VBUSCTRL_U2 (Schematic [1]).
> Presumably this signal is no longer controlled with this change.
>
> This came up in our HAOS issue #2153 [2].

I confirm this issue and I've managed to reproduce it locally. The
mainline is also affected. I will try to prepare a proper patch soon.

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland