Re: [PATCH v10 5/6] usb: dwc3: dwc3-qcom: Enable tx-fifo-resize property by default

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Jun 17, 2021 at 02:58:18AM -0700, Wesley Cheng wrote:
> In order to take advantage of the TX fifo resizing logic, manually add
> these properties to the DWC3 child node by default.  This will allow
> the DWC3 gadget to resize the TX fifos for the IN endpoints, which
> help with performance.
> 
> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 49e6ca9..44e0eaa1 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -645,6 +645,7 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
>  	struct dwc3_qcom	*qcom = platform_get_drvdata(pdev);
>  	struct device_node	*np = pdev->dev.of_node, *dwc3_np;
>  	struct device		*dev = &pdev->dev;
> +	struct property		*prop;
>  	int			ret;
>  
>  	dwc3_np = of_get_compatible_child(np, "snps,dwc3");
> @@ -653,6 +654,14 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> +	prop = devm_kzalloc(dev, sizeof(*prop), GFP_KERNEL);
> +	if (prop) {
> +		prop->name = "tx-fifo-resize";
> +		ret = of_add_property(dwc3_np, prop);
> +		if (ret < 0)
> +			dev_info(dev, "unable to add tx-fifo-resize prop\n");

dev_err()?

And you do not error out properly?


> +	}

No failure if prop is NULL?  This check looks backwards to me, error
paths are in the if () statement, not "all is good".

This feels backwards.

greg k-h