linux-kernel - Re: [PATCH] staging: rtl8723bs: simplify control flow

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Date:   Tue, 12 Apr 2022 23:01:20 -0400
From:   Sevinj Aghayeva <sevinj.aghayeva@...il.com>
To:     Ira Weiny <ira.weiny@...el.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org,
        outreachy linux kernel <outreachy@...ts.linux.dev>
Subject: Re: [PATCH] staging: rtl8723bs: simplify control flow

[Resending again in plain-text mode.]


On Tue, Apr 12, 2022 at 10:59 PM Sevinj Aghayeva
<sevinj.aghayeva@...il.com> wrote:
>
>
>
> On Tue, Apr 12, 2022 at 7:48 PM Ira Weiny <ira.weiny@...el.com> wrote:
>>
>> On Sun, Apr 03, 2022 at 06:42:07PM -0400, Sevinj Aghayeva wrote:
>> > Checkpatch issues "WARNING: else is not generally useful after a break
>> > or return" for the following code:
>> >
>> > while (1) {
>> >       do_join_r = rtw_do_join(padapter);
>> >       if (do_join_r == _SUCCESS) {
>> >               break;
>> >       } else {
>> >               rtw_dec_to_roam(padapter);
>> >
>> >               if (rtw_to_roam(padapter) > 0) {
>> >                       continue;
>> >               } else {
>> >                       rtw_indicate_disconnect(padapter);
>> >                       break;
>> >               }
>> >       }
>> > }
>> >
>> > We simplify this code in multiple steps. First, we remove do_join_r
>>
>> I can't say how Greg would like to see a change like this but my gut says that
>> each of these steps should be a patch in a series...
>>
>> > variable because it is only used right after it is assigned. Second,
>> > we remove the unnecessary else statement right after break:
>> >
>> > while (1) {
>> >       if (rtw_do_join(padapter) == _SUCCESS)
>> >               break;
>> >       rtw_dec_to_roam(padapter);
>> >
>> >       if (rtw_to_roam(padapter) > 0) {
>> >               continue;
>> >       } else {
>> >               rtw_indicate_disconnect(padapter);
>> >               break;
>> >       }
>> > }
>> >
>> > Next, we move the call to rtw_do_join into the while test because the
>> > while will loop only until the call is successful:
>> >
>> > while (rtw_do_join(padapter) != _SUCCESS) {
>> >       rtw_dec_to_roam(padapter);
>> >       if (rtw_to_roam(padapter) > 0) {
>> >               continue;
>> >       } else {
>> >               rtw_indicate_disconnect(padapter);
>> >               break;
>> >       }
>> > }
>> >
>> > Finally, looking at the code above, it is clear that the code will
>> > break out of the loop if rtw_to_roam call is <= 0. Hence:
>> >
>> > while (rtw_do_join(padapter) != _SUCCESS) {
>> >       rtw_dec_to_roam(padapter);
>> >       if (rtw_to_roam(padapter) <= 0) {
>> >               rtw_indicate_disconnect(padapter);
>> >               break;
>> >       }
>> > }
>>
>> ...  that said, this commit message made reviewing the change much easier,
>> thanks.
>
>
> This has landed a week ago, but thanks for the review anyway!
>
>>
>> Did you submit a patch for the r8188eu driver too?  I just noticed it has a
>> similar loop in _rtw_roaming().
>
>
> Right, there is also another similar loop in the same file as well. I think I wasn't sure that this patch was going to get accepted since it was a big change, so I didn't fix the others before this one got it. In the meantime I hit slightly more than 10 cleanup patches and moved on to working with my mentors. But I can fix the other loops if you think I should do it.
>
>>
>> Reviewed-by: Ira Weiny <ira.weiny@...el.com>
>>
>> >
>> > Signed-off-by: Sevinj Aghayeva <sevinj.aghayeva@...il.com>
>> > ---
>> >  drivers/staging/rtl8723bs/core/rtw_mlme.c | 18 ++++--------------
>> >  1 file changed, 4 insertions(+), 14 deletions(-)
>> >
>> > diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme.c b/drivers/staging/rtl8723bs/core/rtw_mlme.c
>> > index 3eacf8f9d236..a45df775d535 100644
>> > --- a/drivers/staging/rtl8723bs/core/rtw_mlme.c
>> > +++ b/drivers/staging/rtl8723bs/core/rtw_mlme.c
>> > @@ -2594,30 +2594,20 @@ void _rtw_roaming(struct adapter *padapter, struct wlan_network *tgt_network)
>> >  {
>> >       struct mlme_priv *pmlmepriv = &padapter->mlmepriv;
>> >       struct wlan_network *cur_network = &pmlmepriv->cur_network;
>> > -     int do_join_r;
>> >
>> >       if (rtw_to_roam(padapter) > 0) {
>> >               memcpy(&pmlmepriv->assoc_ssid, &cur_network->network.ssid, sizeof(struct ndis_802_11_ssid));
>> >
>> >               pmlmepriv->assoc_by_bssid = false;
>> >
>> > -             while (1) {
>> > -                     do_join_r = rtw_do_join(padapter);
>> > -                     if (do_join_r == _SUCCESS) {
>> > +             while (rtw_do_join(padapter) != _SUCCESS) {
>> > +                     rtw_dec_to_roam(padapter);
>> > +                     if (rtw_to_roam(padapter) <= 0) {
>> > +                             rtw_indicate_disconnect(padapter);
>> >                               break;
>> > -                     } else {
>> > -                             rtw_dec_to_roam(padapter);
>> > -
>> > -                             if (rtw_to_roam(padapter) > 0) {
>> > -                                     continue;
>> > -                             } else {
>> > -                                     rtw_indicate_disconnect(padapter);
>> > -                                     break;
>> > -                             }
>> >                       }
>> >               }
>> >       }
>> > -
>> >  }
>> >
>> >  signed int rtw_linked_check(struct adapter *padapter)
>> > --
>> > 2.25.1
>> >
>
>
>
> --
>
> Sevinj.Aghayeva



-- 

Sevinj.Aghayeva