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Message-ID: <797e4962-2ff3-4ae5-a1a7-d4d964fb768d@linutronix.de>
Date: Wed, 20 Dec 2023 17:34:29 +0100
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Subject: Re: [PATCH 19/20] wifi: rtl8xxxu: make supporting AP mode only on
 port 0 transparent
To: Ping-Ke Shih <pkshih@realtek.com>,
 "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Cc: Jes Sorensen <Jes.Sorensen@gmail.com>, Kalle Valo <kvalo@kernel.org>,
 Bitterblue Smith <rtl8821cerfe2@gmail.com>,
 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
References: <20231218143645.433356-1-martin.kaistra@linutronix.de>
 <20231218143645.433356-20-martin.kaistra@linutronix.de>
 <56eed6a3e237435f9d21082ca12eeaec@realtek.com>
Content-Language: de-DE
From: Martin Kaistra <martin.kaistra@linutronix.de>
In-Reply-To: <56eed6a3e237435f9d21082ca12eeaec@realtek.com>
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Am 20.12.23 um 07:28 schrieb Ping-Ke Shih:
> 
> 
>> -----Original Message-----
>> From: Martin Kaistra <martin.kaistra@linutronix.de>
>> Sent: Monday, December 18, 2023 10:37 PM
>> To: linux-wireless@vger.kernel.org
>> Cc: Jes Sorensen <Jes.Sorensen@gmail.com>; Kalle Valo <kvalo@kernel.org>; Ping-Ke Shih
>> <pkshih@realtek.com>; Bitterblue Smith <rtl8821cerfe2@gmail.com>; Sebastian Andrzej Siewior
>> <bigeasy@linutronix.de>
>> Subject: [PATCH 19/20] wifi: rtl8xxxu: make supporting AP mode only on port 0 transparent
>>
>> When the driver is used for concurrent mode, both virtual interfaces can
>> be set to station or AP mode, though only one can be in AP mode at the
>> same time.
>>
>> In order to keep the code simple, use only hw port 0 for AP mode. When
>> an interface is added in AP mode which would be assigned to port 1, use
>> a switch_port function to transparently swap the mapping between virtual
>> interface and hw port.
>>
>> Signed-off-by: Martin Kaistra <martin.kaistra@linutronix.de>
>> ---
>>   .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 84 ++++++++++++++++++-
>>   1 file changed, 82 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> index 88730791091a7..595f447874f4d 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> @@ -6613,6 +6613,84 @@ static int rtl8xxxu_submit_int_urb(struct ieee80211_hw *hw)
>>          return ret;
>>   }
>>
>> +static void rtl8xxxu_switch_ports(struct rtl8xxxu_priv *priv)
>> +{
> 
> [...]
> 
>> +
>> +       vif = priv->vifs[0];
>> +       priv->vifs[0] = priv->vifs[1];
>> +       priv->vifs[1] = vif;
>> +       rtlvif = (struct rtl8xxxu_vif *)priv->vifs[1]->drv_priv;
>> +       rtlvif->port_num = 1;
> 
> nit: Would it be better to swap port_num as well? Currently, port_num of vifs[0]
> will be set to 0 by caller, but not sure if further people could misuse this
> function.

the main reason, I did not include setting port_num for priv->vifs[0], is that 
priv->vifs[0] is a NULL pointer in the current way this function is called from 
rtl8xxxu_add_interface().

do you think it makes sense to add

if (priv->vifs[0])
        rtlvif = (struct rtl8xxxu_vif *)priv->vifs[0]->drv_priv;
        rtlvif->port_num = 0;

just for completeness sake, even though this code path will currently never get 
executed?

> 
> 
>> +}
>> +
>>   static int rtl8xxxu_add_interface(struct ieee80211_hw *hw,
>>                                    struct ieee80211_vif *vif)
>>   {
>> @@ -6640,8 +6718,10 @@ static int rtl8xxxu_add_interface(struct ieee80211_hw *hw,
>>                  }
>>                  break;
>>          case NL80211_IFTYPE_AP:
>> -               if (port_num == 1)
>> -                       return -EOPNOTSUPP;
>> +               if (port_num == 1) {
>> +                       rtl8xxxu_switch_ports(priv);
>> +                       port_num = 0;
>> +               }
>>
>>                  rtl8xxxu_write8(priv, REG_BEACON_CTRL,
>>                                  BEACON_DISABLE_TSF_UPDATE | BEACON_CTRL_MBSSID);
>> --
>> 2.39.2
>