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Message-ID: <997e1858-a499-2188-a6a1-f0c4f0c90079@linutronix.de>
Date:   Fri, 7 Jul 2023 09:23:40 +0200
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Subject: Re: [PATCH v4 00/18] wifi: rtl8xxxu: Add AP mode support for 8188f
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To:     =?UTF-8?Q?Georg_M=c3=bcller?= <georgmueller@gmx.net>,
        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>
References: <20230428150833.218605-1-martin.kaistra@linutronix.de>
 <c9e6a13b-e32d-f810-741c-33598956a55e@gmx.net>
From:   Martin Kaistra <martin.kaistra@linutronix.de>
In-Reply-To: <c9e6a13b-e32d-f810-741c-33598956a55e@gmx.net>
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Hi Georg,

Am 05.07.23 um 11:00 schrieb Georg Müller:
> Hi Martin,
> 
> Am 28.04.23 um 17:08 schrieb Martin Kaistra:
>> This series intends to bring AP mode support to the rtl8xxxu driver,
>> more specifically for the 8188f, because this is the HW I have.
>> The work is based on the vendor driver as I do not have access to
>> datasheets.
> 
> I tried to enable AP mode for a 8188EU device (TP-Link TL-WN725N) with
> some mixed results.
> 
> I added .supports_ap = 1 and .max_macid_num = 16 to rtl8188eu_fops.

According to [1], you might be able to increase max_macid_num to 64.

> 
> The AP was visible and I once was able to connect to it. When connected,
> the link was stable, but I didn't do any benchmarks.
> 
> Most of my tries I was not able to establish a connection (looks like
> timeouts) and once I got this message:
> 
>      usb 1-4: rtl8xxxu_send_beacon_frame: Failed to read beacon valid bit
> 
> The driver I am using currently is the out-of-tree driver rtl8188eu [1],
> which has a stable AP mode, but has some stability issues in managed mode.
> 
> Please give me a hint if and how I may help tracking down the issue to
> enable AP mode for 8188EU as well.

I would suggest the following:
- in rtl8xxxu_fill_txdesc_v3, set macid, HW_SEQ like in the v2 function
- 8188e does decide on the tx rate in software, so 
rtl8188e_handle_ra_tx_report2() will probably need some adjustments to handle 
multiple macids (maybe ra_info in rtl8xxxu_priv should be an array of size 
RTL8XXXU_MAX_MAC_ID_NUM?)

For testing I use a separate machine (or at least separate wifi interface) in 
monitoring mode, which I can set to the correct channel and then see in 
wireshark, if all beacons, ACKs and other frames get sent correctly.

If you have a wireshark trace of a problematic behavior and need some help with 
determining the cause or have some further questions, let me know.

Thanks,
Martin

> 
> Best regards,
> Georg
> 
> [1]
> https://github.com/lwfinger/rtl8188eu/tree/v5.2.2.4


[1] 
https://lore.kernel.org/linux-wireless/27e83382-4c84-1841-c428-d1e5143ea20c@gmail.com/