Date: Tue, 25 May 2021 15:40:13 +0200
From: Fabio Aiuto <fabioaiuto83@gmail.com>
To: Hans de Goede <hdegoede@redhat.com>
Cc: Larry.Finger@lwfinger.net, gregkh@linuxfoundation.org,
	johannes@sipsolutions.net, linux-staging@lists.linux.dev,
	linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org
Subject: Re: staging: rtl8723bs: removal of 5G code
Message-ID: <20210525134012.GA1387@agape.jhs>
References: <20210520092946.GA1404@agape.jhs>
 <8c0c1806-f818-cff0-6925-22ef2b164f77@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <8c0c1806-f818-cff0-6925-22ef2b164f77@redhat.com>
User-Agent: Mutt/1.10.1 (2018-07-13)

Hi Hans and everyone,

On Tue, May 25, 2021 at 12:07:55PM +0200, Hans de Goede wrote:
> Hi,
> 
> On 5/20/21 11:29 AM, Fabio Aiuto wrote:
> > Hi all,
> > 
> > I'm stick with removal of 5Ghz code from rtl8723bs wireless card driver
> > (in staging subsystem).
> > 
> > I think that this task comprehend deletion of all code managing
> > 80Mhz bandwidth and upper bandwidth (160 and 80+80). For the latter
> > it's simple, there's quite no code (unused enums and obsolete comments).
> > 
> > The former seems to be trickier, there are handlers like this:
> > 
> >         /* 3 Set Reg483 */
> >         SubChnlNum = phy_GetSecondaryChnl_8723B(Adapter);
> >         rtw_write8(Adapter, REG_DATA_SC_8723B, SubChnlNum);
> > 
> > phy_GetSecondaryChnl_8723B() contains code like:
> > 
> >         } else if (pHalData->CurrentChannelBW == CHANNEL_WIDTH_40) {
> >                 if (pHalData->nCur40MhzPrimeSC == HAL_PRIME_CHNL_OFFSET_UPPER)
> >                         SCSettingOf20 = VHT_DATA_SC_20_UPPER_OF_80MHZ;
> >                 else if (pHalData->nCur40MhzPrimeSC == HAL_PRIME_CHNL_OFFSET_LOWER)
> >                         SCSettingOf20 = VHT_DATA_SC_20_LOWER_OF_80MHZ;
> >         }
> > 
> > so if we are on a 40M channel some settings involving 80M are made and
> > the whole is then written on card registers.
> 
> I'm no wifi expert, so I was hoping someone else would respond...
> 
> With that said I believe you should keep this else block, this part of the
> function seems to select the order of the bonded channels when bonding
> multiple 20MHz channels together.
> 
> The "if (pHalData->CurrentChannelBW == CHANNEL_WIDTH_80) {}" part can be
> removed because on 2.4G only devices 80 MHz width is not supported, but
> the 40MHz bit should stay, the constants for the register bits may be named
> after the 80MHz option, but I believe these same register bits will impact
> the 40Mhz case too.

agreed, just remove the CHANNEL_WIDTH_80 branch is good

> 
> It might be a good idea to rename the constants to VHT_DATA_SC_20_*_OF_40MHZ
> in a separate patch.

good idea, I was misguided by the trailing *_80MHZ in constant name

> 
> Regards,
> 
> Hans
> 

thank you Hans,

fabio