Subject: Re: [PATCH v1 2/6] usb: chipidea: tegra: Avoid controller/PHY init if bus is externally controlled

From: "Peter Chen (CIX)" <[email-masked]>
Date: Tue, 12 May 2026 09:15:59 +0800

On 26-05-11 16:56:57, Svyatoslav Ryhel wrote:
> If the USB controller and PHY are externally controlled, then the
> registration of the controller and the PHY initialization should be
> skipped, since these configurations must be done by the device that
> controls the bus to work correctly.
> 

I find you only control USB controller device add at PHY driver, most of USB drivers
has PHY control, for chipidea, it has PHY control at core.c, would please try to
adapt for it?

Peter

> Signed-off-by: Svyatoslav Ryhel <[email-masked]>
> ---
>  drivers/usb/chipidea/ci_hdrc_tegra.c | 36 +++++++++++++++++-----------
>  1 file changed, 22 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_tegra.c b/drivers/usb/chipidea/ci_hdrc_tegra.c
> index 372788f0f970..593390a818d1 100644
> --- a/drivers/usb/chipidea/ci_hdrc_tegra.c
> +++ b/drivers/usb/chipidea/ci_hdrc_tegra.c
> @@ -32,6 +32,7 @@ struct tegra_usb {
>  	struct clk *clk;
>  
>  	bool needs_double_reset;
> +	bool externally_controlled;
>  };
>  
>  struct tegra_usb_soc_info {
> @@ -312,20 +313,25 @@ static int tegra_usb_probe(struct platform_device *pdev)
>  	if (device_property_present(&pdev->dev, "nvidia,needs-double-reset"))
>  		usb->needs_double_reset = true;
>  
> +	if (device_property_present(&pdev->dev, "nvidia,external-control"))
> +		usb->externally_controlled = true;
> +
>  	err = tegra_usb_reset_controller(&pdev->dev);
>  	if (err) {
>  		dev_err_probe(&pdev->dev, err, "failed to reset controller");
>  		goto fail_power_off;
>  	}
>  
> -	/*
> -	 * USB controller registers shouldn't be touched before PHY is
> -	 * initialized, otherwise CPU will hang because clocks are gated.
> -	 * PHY driver controls gating of internal USB clocks on Tegra.
> -	 */
> -	err = usb_phy_init(usb->phy);
> -	if (err)
> -		goto fail_power_off;
> +	if (!usb->externally_controlled) {
> +		/*
> +		 * USB controller registers shouldn't be touched before PHY is
> +		 * initialized, otherwise CPU will hang because clocks are gated.
> +		 * PHY driver controls gating of internal USB clocks on Tegra.
> +		 */
> +		err = usb_phy_init(usb->phy);
> +		if (err)
> +			goto fail_power_off;
> +	}
>  
>  	/* setup and register ChipIdea HDRC device */
>  	usb->soc = soc;
> @@ -342,12 +348,14 @@ static int tegra_usb_probe(struct platform_device *pdev)
>  	if (of_usb_get_phy_mode(pdev->dev.of_node) == USBPHY_INTERFACE_MODE_ULPI)
>  		usb->data.flags &= ~CI_HDRC_SUPPORTS_RUNTIME_PM;
>  
> -	usb->dev = ci_hdrc_add_device(&pdev->dev, pdev->resource,
> -				      pdev->num_resources, &usb->data);
> -	if (IS_ERR(usb->dev)) {
> -		err = dev_err_probe(&pdev->dev, PTR_ERR(usb->dev),
> -				    "failed to add HDRC device");
> -		goto phy_shutdown;
> +	if (!usb->externally_controlled) {
> +		usb->dev = ci_hdrc_add_device(&pdev->dev, pdev->resource,
> +					      pdev->num_resources, &usb->data);
> +		if (IS_ERR(usb->dev)) {
> +			err = dev_err_probe(&pdev->dev, PTR_ERR(usb->dev),
> +					    "failed to add HDRC device");
> +			goto phy_shutdown;
> +		}
>  	}
>  
>  	return 0;
> -- 
> 2.51.0
> 

-- 

Best regards,
Peter