Re: [PATCH] mfd: omap-usb-tll: handle clk_prepare return code in usbtll_omap_probe

[Andreas Kemnade <andreas@kemnade.info>]

Am Wed,  6 Nov 2024 23:33:24 +0100
schrieb Karol Przybylski <karprzy7@gmail.com>:

> clk_prepare() is called in usbtll_omap_probe to fill clk array.
> Return code is not checked, leaving possible error condition unhandled.
> 
> Added variable to hold return value from clk_prepare() and return statement
> when it's not successful.
> 
> Found in coverity scan, CID 1594680
> 
> Signed-off-by: Karol Przybylski <karprzy7@gmail.com>
> ---
>  drivers/mfd/omap-usb-tll.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
> index 0f7fdb99c809..28446b082c85 100644
> --- a/drivers/mfd/omap-usb-tll.c
> +++ b/drivers/mfd/omap-usb-tll.c
> @@ -202,7 +202,7 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>  	struct device				*dev =  &pdev->dev;
>  	struct usbtll_omap			*tll;
>  	void __iomem				*base;
> -	int					i, nch, ver;
> +	int					i, nch, ver, err;
>  
>  	dev_dbg(dev, "starting TI HSUSB TLL Controller\n");
>  
> @@ -251,7 +251,11 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>  		if (IS_ERR(tll->ch_clk[i]))
>  			dev_dbg(dev, "can't get clock : %s\n", clkname);

if you add more intensive error checking, then why is this error
ignored and not returned?

>  		else
> -			clk_prepare(tll->ch_clk[i]);
> +			err = clk_prepare(tll->ch_clk[i]);
> +			if (err) {
unnatural braces, if (err) is not in the else branch ?!
> +				dev_err(dev, "Unable to prepare clock\n");
> +				return err;
> +	}
>  	}
>  
>  	pm_runtime_put_sync(dev);
and this one is not called if you return early.

Regards,
Andreas