From: Maxim Skokov <skokovmaksimevg@gmail.com>
To: Ping-Ke Shih <pkshih@realtek.com>
Cc: linux-wireless@vger.kernel.org, Maxim Skokov <skokovmaksimevg@gmail.com>
Subject: rtw89: RTL8851B BTC entry requires unpublished firmware 0.29.133.0
Date: Sat, 5 Sep 2026 16:14:36 +0300 [thread overview]
Message-ID: <20260905131503.6160-1-skokovmaksimevg@gmail.com> (raw)
Hi,
While reading the Wi-Fi/Bluetooth coexistence code in rtw89 I noticed a
BTC version entry for RTL8851B that appears to be unreachable with any
firmware currently available in linux-firmware.
In drivers/net/wireless/realtek/rtw89/coex.c, rtw89_btc_ver_defs[] has
two entries for this chip:
{RTL8851B, RTW89_FW_VER_CODE(0, 29, 133, 0), ... .fcxtrx = 107, ...}
{RTL8851B, RTW89_FW_VER_CODE(0, 29, 29, 0), ... .fcxtrx = 0, ...}
rtw89_coex_recognize_ver() walks the table and selects the first entry
whose fw_ver_code is not greater than the loaded firmware version.
The newest firmware published for this chip in linux-firmware is
0.29.41.5 (rtw89/rtw8851b_fw.bin, updated 2025-11-06; rtw8851b_fw-1.bin
added 2026-02-13). Since 41 < 133, the 0.29.133.0 entry can never be
selected, and every user loading firmware from linux-firmware ends up on
the legacy 0.29.29.0 profile.
On my RTL8851BE with firmware 0.29.41.3 the driver does fall back to the
legacy entry, as expected:
[BTC] use version def[2] = 0x001d1d00
To be clear, I am not reporting a malfunction. I have not observed any
concrete problem that I can attribute to this, and the legacy profile may
well be perfectly adequate. I simply cannot tell how the situation is
meant to be read:
- Is firmware 0.29.133 or newer expected to reach linux-firmware at
some point, with the driver support having landed ahead of it?
- Or is the version code in that entry not what was intended?
Either answer is fine, I would just like to understand it. I have the
hardware and a debug build available, so I am happy to test or collect
logs if that would help.
Thanks,
Maxim Skokov
next reply other threads:[~2026-09-05 13:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-05 13:14 Maxim Skokov [this message]
2026-09-06 4:25 ` rtw89: RTL8851B BTC entry requires unpublished firmware 0.29.133.0 Ping-Ke Shih
2026-09-06 11:58 ` Maxim Skokov
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