Re: [PATCH 2/5] phy: tegra: xusb: Fix USB2 port regulator disable logic

[Diogo Ivo]

On 12/24/25 07:27, Vinod Koul wrote:
> On 04-12-25, 21:27, Diogo Ivo wrote:
> > The USB2 PHY mode handling on Tegra210 incorrectly relied on
> > regulator_is_enabled() when determining whether the VBUS supply should
> > be disabled during role changes. This is because regulator_is_enabled()
> > reports exactly what is states and not if there is an unbalanced number
> > of calls between regulator_enable() and regulator_disable(). For
> > example, regulator_is_enabled() always reports true on a fixed-regulator
> > with no enable gpio, which is the case on the Pixel C.
> >
> > This then leads to the PHY driver wrongfully calling regulator_disable()
> > when transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE since the driver
> > did not previously call the corresponding regulator_enable().
> >
> > Fix this by keeping track of the current role and updating the logic to
> > disable the regulator only when the previous role was USB_ROLE_HOST.
> >
> > While at it fix a small typo in a comment.
>
> Never mix a patch with something else please. More imp if it is fix
> which will go to rcX. Please send a different patch for typo

Ok, will split for v2.

> > Signed-off-by: Diogo Ivo <diogo.ivo@xxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/phy/tegra/xusb-tegra210.c | 5 +++--
> >   drivers/phy/tegra/xusb.h          | 1 +
> >   2 files changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/phy/tegra/xusb-tegra210.c b/drivers/phy/tegra/xusb-tegra210.c
> > index 3409924498e9..63ad57d95514 100644
> > --- a/drivers/phy/tegra/xusb-tegra210.c
> > +++ b/drivers/phy/tegra/xusb-tegra210.c
> > @@ -1934,9 +1934,9 @@ static int tegra210_usb2_phy_set_mode(struct phy *phy, enum phy_mode mode,
> >   			/*
> >   			 * When port is peripheral only or role transitions to
> >   			 * USB_ROLE_NONE from USB_ROLE_DEVICE, regulator is not
> > -			 * be enabled.
> > +			 * enabled.
> >   			 */
> > -			if (regulator_is_enabled(port->supply))
> > +			if (port->role == USB_ROLE_HOST)
> >   				regulator_disable(port->supply);
> >   
> >   			tegra210_xusb_padctl_id_override(padctl, false);
> > @@ -1944,6 +1944,7 @@ static int tegra210_usb2_phy_set_mode(struct phy *phy, enum phy_mode mode,
> >   		}
> >   	}
> >   
> > +	port->role = submode;
> >   	mutex_unlock(&padctl->lock);
> >   
> >   	return err;
> > diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
> > index d2b5f9565132..273af147dfd3 100644
> > --- a/drivers/phy/tegra/xusb.h
> > +++ b/drivers/phy/tegra/xusb.h
> > @@ -317,6 +317,7 @@ struct tegra_xusb_usb2_port {
> >   	enum usb_dr_mode mode;
> >   	bool internal;
> >   	int usb3_port_fake;
> > +	enum usb_role role;
> >   };
>
> Jonathan can we get some t-b for these two patches