Hi Kalle??
?? 2020/8/17 22:26, Kalle Valo д??:
>> 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?
Thanks for you reply, the benefit of this patch is simplify the code,
because in
this function, I don't think the situation of 'devm_clk_get() return
NULL' exists.
So please think about it, thanks.
Tang Bin
>
>> Signed-off-by: Zhang Shengju <[email protected]>
>> Signed-off-by: Tang Bin <[email protected]>
>> ---
>> 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;
> }
>
On Mon, Aug 17, 2020 at 6:43 PM Tang Bin <[email protected]> wrote:
>
> Hi Kalle：
>
> 在 2020/8/17 22:26, Kalle Valo 写道:
> >> 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?
>
> Thanks for you reply, the benefit of this patch is simplify the code,
> because in
>
> this function, I don't think the situation of 'devm_clk_get() return
> NULL' exists.
>
I admit I'm not looking at HEAD, but at least in the two versions I've
got checked out, devm_clk_get() can theoretically return NULL. This
feels like a gratuitous change anyway, but in any case it's wrong and
could cause wrong behavior.
- Steve