[PATCH] hostapd: take configured antenna set into consideration

[Jouni Malinen]

On Wed, Dec 09, 2015 at 12:20:33PM -0800, greearb at candelatech.com wrote:
> If user has configured TX antennas to be less than what
> hardware advertises, the MCS reported by hardware will
> be too large.  So, remove MCS sets accordingly.

The nl80211 related changes seem mostly reasonable, but I'm not sure I
understood what exactly the HT/VHT changes were supposed to do. Why are
they different? HT uses tx_ant & rx_ant and masks values from
cap->supported_mcs_set[] until the highest 1 bit is found. VHT masks
values separately for TX and RX and does this with |= 0x3 << i. Is that
really correct? Should i be "i * 2"? Why is there difference in the
configured bitmap checks (BIT(i) vs. BIT(i - 1) and different i > 0 vs.
i >= 0 condition)?

Is it correct to find the MSB 1 from the values instead of count the
number of 1 bits (configured antennas)?

I'm attaching the cleaned up patches from my work branch. Please provide
any possible updated on top of these.
 
-- 
Jouni Malinen                                            PGP id EFC895FA
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