[PATCH] hostapd: enable STBC only for STBC capable STAs

Jouni Malinen j
Sat Aug 28 02:29:46 PDT 2010

On Fri, May 28, 2010 at 12:13:19PM +0200, Helmut Schaa wrote:
> hostapd simply used its own STBC configuration in the STAs ht caps. This
> resulted in TX STBC being used for STAs not supporting RX STBC, wich in turn
> resulted in the STA not receiving anything.
> Fix this by handling the STBC flags in the same way mac80211 does. Mask out
> RX STBC if we don't support TX STBC and vice versa.

Thanks! Applied. Though, I'm not fully sure whether this covers all
possible cases (even if they might be somewhat unlikely to occur in
practice). The initial step is to take local-ht_cap AND peer-ht_cap and
then mask out the STBC bits in reverse TX/RX case. Would one end be
allowed to support TX STBC only and the other end RX STBC only? If so,
the initial AND operation would clear both bits.. Would hostapd (and
mac80211 for that matter) need to enable STBC in such an asymmetric case
separately? Anyway, this patch looks safer than the previous code, so it
is better starting point even if some additional changes would be

Jouni Malinen                                            PGP id EFC895FA

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