Date:   Tue, 14 Mar 2023 22:27:06 +0100
From:   philipp hortmann <philipp.g.hortmann@gmail.com>
To:     Bitterblue Smith <rtl8821cerfe2@gmail.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        Jes Sorensen <Jes.Sorensen@gmail.com>,
        Ping-Ke Shih <pkshih@realtek.com>, Jiajie Chen <c@jia.je>
Subject: Re: [PATCH v3] wifi: rtl8xxxu: Support new chip RTL8710BU aka
 RTL8188GU
Message-ID: <20230314212706.GA6367@matrix-ESPRIMO-P710>
References: <4edbe29f-00b9-8eef-9789-20bed0b141e2@gmail.com>
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On Mon, Mar 13, 2023 at 03:58:14PM +0200, Bitterblue Smith wrote:
> This chip is found in cheap "free driver" USB adapters from Aliexpress.
> Initially they pretend to be a CD-ROM containing the driver for Windows.
> "Ejecting" switches the device to wifi mode.
> 
> Features: 2.4 GHz, b/g/n mode, 1T1R, 150 Mbps.
> 
> This chip is more unique than other Realtek chips:
> 
> * The registers at addresses 0x0-0xff, which all the other chips use,
>   can't be used here. New registers at 0x8000-0x80ff must be used
>   instead. And it's not a simple matter of adding 0x8000: 0x2
>   (REG_SYS_FUNC) became 0x8004, 0x80 (REG_MCU_FW_DL) became 0x8090,
>   etc.
> 
> * Also there are a few new registers which must be accessed indirectly
>   because their addresses don't fit in 16 bits. No other chips seem to
>   have these.
> 
> * The vendor driver compiles to 8188gu.ko, but the code calls the chip
>   RTL8710B(U) pretty much everywhere, including messages visible to the
>   user.
> 
> Another difference compared to the other chips supported by rtl8xxxu is
> that it has a new PHY status struct, or three of them actually, from
> which we extract the RSSI, among other things. This is not unique,
> though, just new. The chips supported by rtw88 also use it.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Tested Chip: RTL8188EU
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150