[PATCH] phy: renesas: phy-rzg3e-usb3: Fix runtime PM underflow during suspend

[Ovidiu Panait]

Hi Biju,

> 
> Hi Ovidiu,
> 
> Thanks for the patch
> 
> > -----Original Message-----
> > From: Ovidiu Panait <ovidiu.panait.rb at renesas.com>
> > Sent: 27 April 2026 20:48
> > Subject: [PATCH] phy: renesas: phy-rzg3e-usb3: Fix runtime PM underflow
> during suspend
> >
> > On the Renesas RZ/V2H platform, if the xhcd driver is unbound and the
> system is suspended afterwards, a
> > PM underflow error will occur:
> >
> >  # echo 15850000.usb > /sys/bus/platform/drivers/xhci-renesas-hcd/unbind
> >  # systemctl suspend
> >  15870000.usb-phy: PM: dpm_run_callback(): genpd_resume_noirq returns -
> 13
> >  15870000.usb-phy: PM: failed to resume noirq: error -13
> >  15870000.usb-phy: Runtime PM usage count underflow!
> >
> > Since the PHY framework is managing the runtime PM of the PHY via
> phy_power_on()/phy_power_off(), there
> > is no need for the PHY driver to manipulate the runtime PM state during
> suspend.
> >
> > To fix this, remove the runtime PM calls from the suspend/resume paths
> and add a get/put pair inside
> > rzg3e_phy_usb3_init_helper() to make sure the clock is enabled during
> init, even when there is no
> > consumer for the PHY.
> >
> > Also, change the suspend ops from NOIRQ_SYSTEM_SLEEP_PM_OPS to
> SYSTEM_SLEEP_PM_OPS because runtime PM
> > is disabled during the noirq phase and pm_runtime_resume_and_get() would
> not actually enable the device
> > clock.
> >
> > Fixes: ee5f1a3f90a4 ("phy: renesas: Add Renesas RZ/G3E USB3.0 PHY
> driver")
> > Signed-off-by: Ovidiu Panait <ovidiu.panait.rb at renesas.com>
> > ---
> >  drivers/phy/renesas/phy-rzg3e-usb3.c | 31 ++++++++++++++++------------
> >  1 file changed, 18 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/phy/renesas/phy-rzg3e-usb3.c
> b/drivers/phy/renesas/phy-rzg3e-usb3.c
> > index 6b3453ea0004..055775e1a0f7 100644
> > --- a/drivers/phy/renesas/phy-rzg3e-usb3.c
> > +++ b/drivers/phy/renesas/phy-rzg3e-usb3.c
> > @@ -64,6 +64,7 @@
> >  #define USB3_TEST_LANECONFIG0_DEFAULT		(0xd)
> >
> >  struct rz_usb3 {
> > +	struct device *dev;
> 
> Do you need dev as struct phy has dev member [1]?
> 
> [1]
> https://elixir.bootlin.com/linux/v6.0-
> rc4/source/include/linux/phy/phy.h#L153
> 
> >  	void __iomem *base;
> >  	struct reset_control *rstc;
> >  	bool skip_reinit;
> > @@ -130,11 +131,21 @@ static int rzg3e_phy_usb3test_phy_init(void
> __iomem *base)
> >  	return 0;
> >  }
> >
> > -static int rzg3e_phy_usb3_init_helper(void __iomem *base)
> 
> you can add one more function parameter dev here.
> 
> static int rzg3e_phy_usb3_init_helper(struct device *dev, void __iomem
> *base)
> 
> > +static int rzg3e_phy_usb3_init_helper(struct rz_usb3 *r)
> >  {
> > -	rzg3e_phy_usb2test_phy_init(base);
> > +	int ret;
> > +
> > +	ret = pm_runtime_resume_and_get(r->dev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	rzg3e_phy_usb2test_phy_init(r->base);
> >
> > -	return rzg3e_phy_usb3test_phy_init(base);
> > +	ret = rzg3e_phy_usb3test_phy_init(r->base);
> > +
> > +	pm_runtime_put_sync(r->dev);
> > +
> > +	return ret;
> >  }
> >
> >  static int rzg3e_phy_usb3_init(struct phy *p) @@ -143,7 +154,7 @@
> static int
> > rzg3e_phy_usb3_init(struct phy *p)
> >  	int ret = 0;
> >
> >  	if (!r->skip_reinit)
> > -		ret = rzg3e_phy_usb3_init_helper(r->base);
> > +		ret = rzg3e_phy_usb3_init_helper(r);
> 
> ret = rzg3e_phy_usb3_init_helper(&p->dev, r->base);
> 
> >
> >  	return ret;
> >  }
> > @@ -187,6 +198,7 @@ static int rzg3e_phy_usb3_probe(struct
> platform_device *pdev)
> >
> >  	platform_set_drvdata(pdev, r);
> 
> >  	phy_set_drvdata(phy, r);
> > +	r->dev = dev;
> 
> Drop this.
> 
> >
> >  	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> >  	if (IS_ERR(provider))
> > @@ -199,7 +211,6 @@ static int rzg3e_phy_usb3_suspend(struct device
> *dev)  {
> >  	struct rz_usb3 *r = dev_get_drvdata(dev);
> >
> > -	pm_runtime_put(dev);
> >  	reset_control_assert(r->rstc);
> >  	r->skip_reinit = false;
> >
> > @@ -215,27 +226,21 @@ static int rzg3e_phy_usb3_resume(struct device
> *dev)
> >  	if (ret)
> >  		return ret;
> >
> > -	ret = pm_runtime_resume_and_get(dev);
> > +	ret = rzg3e_phy_usb3_init_helper(r);
> 
> 	ret = rzg3e_phy_usb3_init_helper(dev, r->base);

"dev" is the platform device, which is different from phy->dev. Phy->dev
is a child of the platform device.

We could be referencing the platform device from phy->dev with &phy->dev.parent,
but I don't think that will make the code cleaner.

Considering this, I think the current implementation is fine.

Ovidiu


> 
> With the above addressed,
> 
> Reviewed-by: Biju Das <biju.das.jz at bp.renesas.com>
> 
> Cheers,
> Biju
> 
> >  	if (ret)
> >  		goto reset_assert;
> >
> > -	ret = rzg3e_phy_usb3_init_helper(r->base);
> > -	if (ret)
> > -		goto pm_put;
> > -
> >  	r->skip_reinit = true;
> >
> >  	return 0;
> >
> > -pm_put:
> > -	pm_runtime_put(dev);
> >  reset_assert:
> >  	reset_control_assert(r->rstc);
> >  	return ret;
> >  }
> >
> >  static const struct dev_pm_ops rzg3e_phy_usb3_pm = {
> > -	NOIRQ_SYSTEM_SLEEP_PM_OPS(rzg3e_phy_usb3_suspend,
> rzg3e_phy_usb3_resume)
> > +	SYSTEM_SLEEP_PM_OPS(rzg3e_phy_usb3_suspend, rzg3e_phy_usb3_resume)
> >  };
> >
> >  static const struct of_device_id rzg3e_phy_usb3_match_table[] = {
> > --
> > 2.34.1