Re: [PATCH] usb: dwc3: qcom: allocate clks with main struct

[Thinh Nguyen]

On Fri, Apr 10, 2026, Rosen Penev wrote:
> Use a flexible array member to combine allocations.
> 
> Add __counted_by for extra runtime analysis.
> 
> Change dwc3_qcom_clk_init to a single parameter. No need to pass count
> separately now.
> 
> Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> ---
>  drivers/usb/dwc3/dwc3-qcom-legacy.c | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom-legacy.c b/drivers/usb/dwc3/dwc3-qcom-legacy.c
> index d3fad0fcfdac..565d03eb01b8 100644
> --- a/drivers/usb/dwc3/dwc3-qcom-legacy.c
> +++ b/drivers/usb/dwc3/dwc3-qcom-legacy.c
> @@ -74,7 +74,6 @@ struct dwc3_qcom {
>  	struct device		*dev;
>  	void __iomem		*qscratch_base;
>  	struct platform_device	*dwc3;
> -	struct clk		**clks;
>  	int			num_clocks;
>  	struct reset_control	*resets;
>  	struct dwc3_qcom_port	ports[DWC3_QCOM_MAX_PORTS];
> @@ -90,6 +89,7 @@ struct dwc3_qcom {
>  	bool			pm_suspended;
>  	struct icc_path		*icc_path_ddr;
>  	struct icc_path		*icc_path_apps;
> +	struct clk		*clks[] __counted_by(num_clocks);
>  };
>  
>  static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
> @@ -653,10 +653,11 @@ static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
> +static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom)
>  {
>  	struct device		*dev = qcom->dev;
>  	struct device_node	*np = dev->of_node;
> +	int			count = qcom->num_clocks;
>  	int			i;
>  
>  	if (!np || !count)
> @@ -665,13 +666,6 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
>  	if (count < 0)
>  		return count;
>  
> -	qcom->num_clocks = count;
> -
> -	qcom->clks = devm_kcalloc(dev, qcom->num_clocks,
> -				  sizeof(struct clk *), GFP_KERNEL);
> -	if (!qcom->clks)
> -		return -ENOMEM;
> -
>  	for (i = 0; i < qcom->num_clocks; i++) {
>  		struct clk	*clk;
>  		int		ret;
> @@ -736,13 +730,18 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	struct device		*dev = &pdev->dev;
>  	struct dwc3_qcom	*qcom;
>  	int			ret, i;
> +	int			num_clocks;
>  	bool			ignore_pipe_clk;
>  	bool			wakeup_source;
>  
> -	qcom = devm_kzalloc(&pdev->dev, sizeof(*qcom), GFP_KERNEL);
> +	num_clocks = of_clk_get_parent_count(np);
> +	qcom = devm_kzalloc(&pdev->dev, struct_size(qcom, clks, num_clocks),
> +			GFP_KERNEL);
>  	if (!qcom)
>  		return -ENOMEM;
>  
> +	qcom->num_clocks = num_clocks;
> +
>  	platform_set_drvdata(pdev, qcom);
>  	qcom->dev = &pdev->dev;
>  
> @@ -766,7 +765,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  		goto reset_assert;
>  	}
>  
> -	ret = dwc3_qcom_clk_init(qcom, of_clk_get_parent_count(np));
> +	ret = dwc3_qcom_clk_init(qcom);
>  	if (ret) {
>  		dev_err_probe(dev, ret, "failed to get clocks\n");
>  		goto reset_assert;
> -- 
> 2.53.0
> 

I don't see how this is better than before, especially when it's
deviating from the new dwc3-qcom logic. Please review the dwc3-qcom
instead before making changes to the legacy driver. I prefer new
development to be done in the new dwc3-qcom driver.

Thanks,
Thinh