Re: [PATCH rtw-next v3 1/5] wifi: rtw88: 8812a, 8814a: enable STBC for HT transmissions

[Luka Gejak <luka.gejak@linux.dev>]

Hi Jie Feng,

Thanks for adding the 8822c note. One question below.

On November 12, 2026 6:32:40 PM GMT+01:00, Ho Jie Feng <hjf3108@gmail.com>
wrote:

> 8812a and 8814a support STBC, enable it.

The hardware seems to support it. The vendor driver reports TX STBC for
both chips unless they are 1T1R or 1T2R. But it keeps HT STBC TX off by
default, os_dep/linux/os_intfs.c in the 8812au driver has

        int rtw_stbc_cap = 0x13;

and rtw_ht_use_default_setting() only enables HT STBC TX for BIT5, which
is not set there. VHT STBC TX (BIT1) is on. In rtw88 only 8822c has it,
from 81a68a1424ba ("rtw88: 8822c: add tx stbc support under HT mode"),
while 8822b stays off although it is 2T2R as well.

As far as I can see, a VHT peer already gets STBC through the VHT TX
STBC capability we advertise for rf_path_num > 1, so this patch only
changes HT peers, for example any AP on 2.4 GHz, where we don't
advertise VHT. Did you test it there or with an HT only AP? The numbers
in the cover letter would only show this patch if the test was done
that way.

Best regards,
Luka Gejak