Re: [PATCH] usb: dwc3: move core validation to be after clks enable

[Sriharsha Allenki <sallenki@xxxxxxxxxxxxxx>]

Hi Jun Li,

On 5/8/2019 9:54 AM, Jun Li wrote:
> From: Jun Li <jun.li@xxxxxxx>
>
> Register access in core validation may hang before the bulk
> clks are enabled.
>
> Fixes: b873e2d0ea1e ("usb: dwc3: Do core validation early on probe")
> Signed-off-by: Jun Li <jun.li@xxxxxxx>
> ---
>   drivers/usb/dwc3/core.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 4aff1d8..0e49ff3 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1423,11 +1423,6 @@ static int dwc3_probe(struct platform_device *pdev)
>   	dwc->regs	= regs;
>   	dwc->regs_size	= resource_size(&dwc_res);
>   
> -	if (!dwc3_core_is_valid(dwc)) {
> -		dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
> -		return -ENODEV;
> -	}
> -
>   	dwc3_get_properties(dwc);
>   
>   	dwc->reset = devm_reset_control_get_optional_shared(dev, NULL);
> @@ -1460,6 +1455,11 @@ static int dwc3_probe(struct platform_device *pdev)
>   	if (ret)
>   		goto unprepare_clks;
>   
> +	if (!dwc3_core_is_valid(dwc)) {
> +		dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");

Please update "ret" here with -ENODEV, else the probe call will return 
success (ret is 0).

> +		goto disable_clks;
> +	}
> +
>   	platform_set_drvdata(pdev, dwc);
>   	dwc3_cache_hwparams(dwc);
>   
> @@ -1524,7 +1524,7 @@ static int dwc3_probe(struct platform_device *pdev)
>   err1:
>   	pm_runtime_put_sync(&pdev->dev);
>   	pm_runtime_disable(&pdev->dev);
> -
> +disable_clks:
>   	clk_bulk_disable(dwc->num_clks, dwc->clks);
>   unprepare_clks:
>   	clk_bulk_unprepare(dwc->num_clks, dwc->clks);

Regards,

Sriharsha