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

From: Stanley Chang[昌育德]
Date: Sun Nov 05 2023 - 22:48:55 EST



> 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>

Tested-by: Stanley Chang <stanley_chang@xxxxxxxxxxx>