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

[Vinod Koul <vkoul@kernel.org>]

On 27-04-26, 19:47, Ovidiu Panait wrote:
> 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.

Ok

> 
> 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.

This is a fix, so split this up please

> 
> Fixes: ee5f1a3f90a4 ("phy: renesas: Add Renesas RZ/G3E USB3.0 PHY driver")
> Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@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;

This does not belong in a fix, please split

>  	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)
> +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);
>  
>  	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;
>  
>  	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);
>  	if (ret)
>  		goto reset_assert;
>  
> -	ret = rzg3e_phy_usb3_init_helper(r->base);
> -	if (ret)
> -		goto pm_put;
> -
>  	r->skip_reinit = true;

https://sashiko.dev/#/patchset/20260427194741.161533-1-ovidiu.panait.rb%40renesas.com


-- 
~Vinod