Re: [PATCH] ath10k: fix the status check and wrong return

[Kalle Valo <kvalo@codeaurora.org>]

Tang Bin <tangbin@cmss.chinamobile.com> writes:

> In the function ath10k_ahb_clock_init(), devm_clk_get() doesn't
> return NULL. Thus use IS_ERR() and PTR_ERR() to validate
> the returned value instead of IS_ERR_OR_NULL().

Why? What's the benefit of this patch? Or what harm does
IS_ERR_OR_NULL() create?

> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> ---
>  drivers/net/wireless/ath/ath10k/ahb.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/ahb.c b/drivers/net/wireless/ath/ath10k/ahb.c
> index ed87bc00f..ea669af6a 100644
> --- a/drivers/net/wireless/ath/ath10k/ahb.c
> +++ b/drivers/net/wireless/ath/ath10k/ahb.c
> @@ -87,24 +87,24 @@ static int ath10k_ahb_clock_init(struct ath10k *ar)
>  	dev = &ar_ahb->pdev->dev;
>  
>  	ar_ahb->cmd_clk = devm_clk_get(dev, "wifi_wcss_cmd");
> -	if (IS_ERR_OR_NULL(ar_ahb->cmd_clk)) {
> +	if (IS_ERR(ar_ahb->cmd_clk)) {
>  		ath10k_err(ar, "failed to get cmd clk: %ld\n",
>  			   PTR_ERR(ar_ahb->cmd_clk));
> -		return ar_ahb->cmd_clk ? PTR_ERR(ar_ahb->cmd_clk) : -ENODEV;
> +		return PTR_ERR(ar_ahb->cmd_clk);
>  	}

devm_clk_get() can return NULL if CONFIG_HAVE_CLK is disabled:

static inline struct clk *devm_clk_get(struct device *dev, const char *id)
{
	return NULL;
}

-- 
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches