linux-kernel - Re: [PATCH] staging: rtl8723bs: Use min/max macros for variable comparison

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Message-ID: <Y2N5nuF9a62KPN3s@qemulion>
Date:   Thu, 3 Nov 2022 13:49:42 +0530
From:   Deepak R Varma <drv@...lo.com>
To:     Julia Lawall <julia.lawall@...ia.fr>
Cc:     outreachy@...ts.linux.dev,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] staging: rtl8723bs: Use min/max macros for variable
 comparison

On Thu, Nov 03, 2022 at 08:55:32AM +0100, Julia Lawall wrote:
>
>
> On Thu, 3 Nov 2022, Deepak R Varma wrote:
>
> > Simplify code by using min and max helper macros in place of lengthy
> > if/else block oriented logical evaluation and value assignment. This
> > issue is identified by coccicheck using the minmax.cocci file.
> >
> > Signed-off-by: Deepak R Varma <drv@...lo.com>
> > ---
> >
> > Please note:
> >    1. Using min for max_AMPDU_len computation warning was NOT auto generated by
> >       the cocciecheck command. This was caught while surround code review and
> >       was manually changed.
> >    2. Checkpatch script continues to complaint about min_MPDU_spacing
> >       computation line being more than 100 character in length. I did not find a
> >       better formatting that will address this checkpatch warning. Any
> >       suggestions are most welcome.
> >    3. Proposed changes are compile tested only on my x86 based VM.
> >
> >
> >  drivers/staging/rtl8723bs/core/rtw_wlan_util.c | 12 ++++--------
> >  drivers/staging/rtl8723bs/hal/odm_DIG.c        |  5 +----
> >  2 files changed, 5 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
> > index 18ba846c0b7b..dcda587b84bc 100644
> > --- a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
> > +++ b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
> > @@ -986,15 +986,11 @@ void HT_caps_handler(struct adapter *padapter, struct ndis_80211_var_ie *pIE)
> >  			pmlmeinfo->HT_caps.u.HT_cap[i] &= (pIE->data[i]);
> >  		} else {
> >  			/* modify from  fw by Thomas 2010/11/17 */
> > -			if ((pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x3) > (pIE->data[i] & 0x3))
> > -				max_AMPDU_len = (pIE->data[i] & 0x3);
> > -			else
> > -				max_AMPDU_len = (pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x3);
> > +			max_AMPDU_len = min((pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x3),
> > +					    (pIE->data[i] & 0x3));
> >
> > -			if ((pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x1c) > (pIE->data[i] & 0x1c))
> > -				min_MPDU_spacing = (pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x1c);
> > -			else
> > -				min_MPDU_spacing = (pIE->data[i] & 0x1c);
> > +			min_MPDU_spacing = max((pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x1c),
> > +					       (pIE->data[i] & 0x1c));
>
> There seem to be a lot of unnecessary parentheses.  Admittedly they were
> there before, but since you are creating the max call from scratch in this
> patch, perhaps the parentheses around the arguments could be dropped at
> the same time.

Sounds good. I will improve further and send in a revision.

Also, do you have a comment on why coccicheck did not catch the min opportunity
for max_AMPDU_len computation? I am not seeing anything different with the
if/else blocks here.

Thank you,
./drv

>
> julia
>
> >
> >  			pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para = max_AMPDU_len | min_MPDU_spacing;
> >  		}
> > diff --git a/drivers/staging/rtl8723bs/hal/odm_DIG.c b/drivers/staging/rtl8723bs/hal/odm_DIG.c
> > index 07edf74ccfe5..97a51546463a 100644
> > --- a/drivers/staging/rtl8723bs/hal/odm_DIG.c
> > +++ b/drivers/staging/rtl8723bs/hal/odm_DIG.c
> > @@ -598,10 +598,7 @@ void odm_DIGbyRSSI_LPS(void *pDM_VOID)
> >  	/* Lower bound checking */
> >
> >  	/* RSSI Lower bound check */
> > -	if ((pDM_Odm->RSSI_Min-10) > DM_DIG_MIN_NIC)
> > -		RSSI_Lower = pDM_Odm->RSSI_Min-10;
> > -	else
> > -		RSSI_Lower = DM_DIG_MIN_NIC;
> > +	RSSI_Lower = max(pDM_Odm->RSSI_Min - 10, DM_DIG_MIN_NIC);
> >
> >  	/* Upper and Lower Bound checking */
> >  	if (CurrentIGI > DM_DIG_MAX_NIC)
> > --
> > 2.34.1
> >
> >
> >
> >
> >
>