Re: [PATCH] Revert "usb: dwc3: disable USB core PHY management"

[Thinh Nguyen]

On Thu, Nov 03, 2022, Johan Hovold wrote:
> This reverts commit 6000b8d900cd5f52fbcd0776d0cc396e88c8c2ea.
> 
> The offending commit disabled the USB core PHY management as the dwc3
> already manages the PHYs in question.
> 
> Unfortunately some platforms have started relying on having USB core
> also controlling the PHY and this is specifically currently needed on
> some Exynos platforms for PHY calibration or connected device may fail
> to enumerate.
> 
> The PHY calibration was previously handled in the dwc3 driver, but to
> work around some issues related to how the dwc3 driver interacts with
> xhci (e.g. using multiple drivers) this was moved to USB core by commits
> 34c7ed72f4f0 ("usb: core: phy: add support for PHY calibration") and
> a0a465569b45 ("usb: dwc3: remove generic PHY calibrate() calls").
> 
> The same PHY obviously should not be controlled from two different
> places, which for example do no agree on the PHY mode or power state
> during suspend, but as the offending patch was backported to stable,
> let's revert it for now.
> 
> Reported-by: Stefan Agner <stefan@xxxxxxxx>
> Link: https://urldefense.com/v3/__https://lore.kernel.org/lkml/808bdba846bb60456adf10a3016911ee@xxxxxxxx/__;!!A4F2R9G_pg!alHoICKQIGg3RelD-tXOswfNBGy3QtLU4e9jazfXshXj1WeYF8LMgybbqHDrfszazJ9ywa1BdVX0i8gewLUmrvz2_mxX$ 
> Fixes: 6000b8d900cd ("usb: dwc3: disable USB core PHY management")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
> ---
>  drivers/usb/dwc3/host.c | 10 ----------
>  1 file changed, 10 deletions(-)
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

Thanks,
Thinh