[PATCH] mac80211: fix incorrect nss config

[Johannes Berg]

On Mon, 2021-09-27 at 19:11 +0530, Thiraviyam Mariyappan wrote:
> In HE capabilities, HE-MCS Rx map field filled with value 0x3 for all eight
> spatial streams if txrx chains configured as incorrect value.
> This patch changes configure at least single spatial stream for HE-MCS
> 0 to 7 in all supported channel widths if nss configured as incorrect
> value.
> 
> Signed-off-by: Thiraviyam Mariyappan <tmariyap at codeaurora.org>
> ---
>  net/mac80211/he.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/net/mac80211/he.c b/net/mac80211/he.c
> index c05af70..ee113ff5 100644
> --- a/net/mac80211/he.c
> +++ b/net/mac80211/he.c
> @@ -151,6 +151,13 @@ ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
>  		       &he_cap_ie[sizeof(he_cap->he_cap_elem) + mcs_nss_size],
>  		       he_ppe_size);
>  
> 
> +	if (he_cap->he_mcs_nss_supp.rx_mcs_80 == cpu_to_le16(0xFFFF)) {
> +		he_cap->has_he = false;
> +		sdata_info(sdata, "Ignoring HE IE from %pM due to incorrect rx_mcs_80\n",
> +			   sta->addr);
> +		return;
> +	}

Like so many other workarounds, this should probably come with a comment
as to _why_ we're doing this, ideally including the model/firmware
version ...

johannes