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

[Biju Das]

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);

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