Re: [PATCH] USB: xhci-plat: fix legacy PHY double inity

[Stefan Eichenberger]

On Fri, Nov 03, 2023 at 05:43:23PM +0100, Johan Hovold wrote:
> Commits 7b8ef22ea547 ("usb: xhci: plat: Add USB phy support") and
> 9134c1fd0503 ("usb: xhci: plat: Add USB 3.0 phy support") added support
> for looking up legacy PHYs from the sysdev devicetree node and
> initialising them.
> 
> This broke drivers such as dwc3 which manages PHYs themself as the PHYs
> would now be initialised twice, something which specifically can lead to
> resources being left enabled during suspend (e.g. with the
> usb_phy_generic PHY driver).
> 
> As the dwc3 driver uses driver-name matching for the xhci platform
> device, fix this by only looking up and initialising PHYs for devices
> that have been matched using OF.
> 
> Note that checking that the platform device has a devicetree node would
> currently be sufficient, but that could lead to subtle breakages in case
> anyone ever tries to reuse an ancestor's node.
> 
> Fixes: 7b8ef22ea547 ("usb: xhci: plat: Add USB phy support")
> Fixes: 9134c1fd0503 ("usb: xhci: plat: Add USB 3.0 phy support")
> Cc: stable@xxxxxxxxxxxxxxx      # 4.1
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Stanley Chang <stanley_chang@xxxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>

Tested-by: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>