Re: [RFC v3 4/8] wifi: mac80211: add support for DFS with multiple radios

[Karthikeyan Periyasamy <quic_periyasa@quicinc.com>]

On 6/6/2024 11:37 PM, Felix Fietkau wrote:
> DFS can be supported with multi-channel combinations, as long as each DFS
> capable radio only supports one channel.
> 
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> ---
>   net/mac80211/main.c | 32 ++++++++++++++++++++++++--------
>   1 file changed, 24 insertions(+), 8 deletions(-)
> 
> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
> index 40fbf397ce74..e9c4cf611e94 100644
> --- a/net/mac80211/main.c
> +++ b/net/mac80211/main.c
> @@ -1084,6 +1084,21 @@ static int ieee80211_init_cipher_suites(struct ieee80211_local *local)
>   	return 0;
>   }
>   
> +static bool
> +ieee80211_ifcomb_check_radar(const struct ieee80211_iface_combination *comb,
> +			     int n_comb)
> +{
> +	int i;
> +
> +	/* DFS is not supported with multi-channel combinations yet */
> +	for (i = 0; i < n_comb; i++, comb++)
> +		if (comb->radar_detect_widths &&
> +		    comb->num_different_channels > 1)
> +			return false;
> +
> +	return true;
> +}
> +
>   int ieee80211_register_hw(struct ieee80211_hw *hw)
>   {
>   	struct ieee80211_local *local = hw_to_local(hw);
> @@ -1173,17 +1188,18 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
>   			if (comb->num_different_channels > 1)
>   				return -EINVAL;
>   		}
> -	} else {
> -		/* DFS is not supported with multi-channel combinations yet */
> -		for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
> -			const struct ieee80211_iface_combination *comb;
> -
> -			comb = &local->hw.wiphy->iface_combinations[i];
> +	} else if (hw->wiphy->n_radio) {
> +		for (i = 0; i < hw->wiphy->n_radio; i++) {
> +			const struct wiphy_radio *radio = &hw->wiphy->radio[i];
>   
> -			if (comb->radar_detect_widths &&
> -			    comb->num_different_channels > 1)
> +			if (!ieee80211_ifcomb_check_radar(radio->iface_combinations,
> +							  radio->n_iface_combinations))
>   				return -EINVAL;
>   		}

When driver advertise per radio iface combination, you are not checking 
the global iface combination. using the uncheck global iface combination 
lead to unknown issues.


> +	} else {
> +		if (!ieee80211_ifcomb_check_radar(hw->wiphy->iface_combinations,
> +						  hw->wiphy->n_iface_combinations))
> +			return -EINVAL;
>   	}
>   
>   	/* Only HW csum features are currently compatible with mac80211 */

-- 
Karthikeyan Periyasamy
--
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