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

Stefan Agner
2022-10-26T13:11:11Z

On 2022-10-21 08:54, Johan Hovold wrote:
> On Fri, Oct 21, 2022 at 12:06:12AM +0200, Stefan Agner wrote:
>> On 2022-10-19 10:59, Johan Hovold wrote:
>> > On Tue, Oct 18, 2022 at 05:27:24PM +0200, Stefan Agner wrote:
>> >> 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.
>
>> >> For some reason, this commit seems to break detection of the USB to
>> >> S-ATA controller on ODROID-HC1 devices (Exynos 5422).
>
>> > I think this may be related to the calibration calls added to dwc3 and
>> > later removed again by commits:
>> >
>> > d8c80bb3b55b ("phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800")
>> > a0a465569b45 ("usb: dwc3: remove generic PHY calibrate() calls")
>> >
>> > The removal explicitly mentions that the expectation is that USB core
>> > will do the PHY calibration.
>> >
>> > There could be other changes in the sequencing of events that this
>> > platform has been implicitly relying on, but as a start, could try
>> > adding the missing calibration calls (patch below) and see if that makes a
>> > difference?
>>
>> The patch below did not apply to 5.15.74 directly, but I think I was
>> able to get the corrected patch applied (see below)
>
> Looks good to me.
>
>> That said, I do not have direct access to that hardware, but I created a
>> build and asked the user test it.
>
> Thanks, let me know how it goes.

The user reports the S-ATA disk is *not* recognized with that patch
applied.

--
Stefan