Re: [PATCH v8 6/6] phy: fsl-imx8mq-usb: keep PHY power domain runtime always-on for i.MX8MP

[Frank Li]

On Fri, Jul 31, 2026 at 04:11:24PM +0800, Xu Yang wrote:
> From: Xu Yang <xu.yang_2@xxxxxxx>
>
> On i.MX8MP, the USB PHY has a dedicated power domain that was previously
> never powered off at runtime. With the introduction of runtime PM support,
> the power domain will be powered off if the device is runtime suspended,
> which breaks USB wakeup functionality.
>
> To preserve wakeup functionality, mark the PHY power domain as runtime
> always-on for i.MX8MP platform. To limit the behavior to i.MX8MP, add a
> need_genpd_rpm_on to imx8mq_usb_phy_drvdata and set it as true for i.MX8MP.
>
> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>
> ---
> Changes in v8:
>  - no changes
> Changes in v7:
>  - replace dev_err_probe() with dev_warn()
> Changes in v6:
>  - set need_genpd_rpm_on flag for i.MX8MP and call dev_pm_genpd_rpm_always_on()
>    if the flag is true
> Changes in v5:
>  - no changes
> Changes in v4:
>  - no changes
> Changes in v3:
>  - new patch
> ---
>  drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> index ba7603a008d8..8859835541b1 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> @@ -9,6 +9,7 @@
>  #include <linux/of.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/regmap.h>
> @@ -134,6 +135,7 @@ struct imx8mq_usb_phy {
>
>  struct imx8mq_usb_phy_drvdata {
>  	const struct phy_ops *ops;
> +	bool need_genpd_rpm_on;
>  };
>
>  static void tca_blk_orientation_set(struct tca_blk *tca,
> @@ -669,6 +671,7 @@ static const struct imx8mq_usb_phy_drvdata imx8mq_usb_phy_data = {
>
>  static const struct imx8mq_usb_phy_drvdata imx8mp_usb_phy_data = {
>  	.ops = &imx8mp_usb_phy_ops,
> +	.need_genpd_rpm_on = true,
>  };
>
>  static const struct imx8mq_usb_phy_drvdata imx95_usb_phy_data = {
> @@ -738,6 +741,12 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
>  	if (!phy_data)
>  		return -EINVAL;
>
> +	if (phy_data->need_genpd_rpm_on) {
> +		ret = dev_pm_genpd_rpm_always_on(dev, true);
> +		if (ret && ret != -EOPNOTSUPP)
> +			dev_warn(dev, "failed to set genpd rpm always on\n");
> +	}
> +
>  	pm_runtime_set_active(dev);
>  	pm_runtime_enable(dev);
>
>
> --
> 2.34.1
>
>