Re: [PATCH] ath5k: fix WARNING opportunity for swap.

From: Mahmoud Matook
Date: Tue Aug 08 2023 - 17:13:38 EST


On 08/08, Jiri Slaby wrote:

> On 07. 08. 23, 22:10, Mahmoud Maatuq wrote:
> > coccinielle reported the following:
> > ./drivers/net/wireless/ath/ath5k/phy.c:1573:25-26: WARNING opportunity for swap()
>
>
> OK, once again:
> https://lore.kernel.org/all/0c3acbd4-6ab2-5cc5-6293-54e30093cce2@xxxxxxxxxx/


I had a look at the commit history, to see why the original developer
didn't use sort() function, and name the array variable sort but found
nothing.
I have some doubts that he might did that intentionally, so not to call
sort() function for such small array and avoid the cost of context
switching.


> > Signed-off-by: Mahmoud Maatuq <mahmoudmatook.mm@xxxxxxxxx>
> > ---
> > drivers/net/wireless/ath/ath5k/phy.c | 5 +----
> > 1 file changed, 1 insertion(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
> > index 5797ef9c73d7..f87eb684f223 100644
> > --- a/drivers/net/wireless/ath/ath5k/phy.c
> > +++ b/drivers/net/wireless/ath/ath5k/phy.c
> > @@ -1562,16 +1562,13 @@ static s16
> > ath5k_hw_get_median_noise_floor(struct ath5k_hw *ah)
> > {
> > s16 sort[ATH5K_NF_CAL_HIST_MAX];
> > - s16 tmp;
> > int i, j;
> > memcpy(sort, ah->ah_nfcal_hist.nfval, sizeof(sort));
> > for (i = 0; i < ATH5K_NF_CAL_HIST_MAX - 1; i++) {
> > for (j = 1; j < ATH5K_NF_CAL_HIST_MAX - i; j++) {
> > if (sort[j] > sort[j - 1]) {
> > - tmp = sort[j];
> > - sort[j] = sort[j - 1];
> > - sort[j - 1] = tmp;
> > + swap(sort[j], sort[j - 1]);
> > }
> > }
> > }
>
> --
> js
> suse labs