[PATCH V4 1/6] bss coloring: add support for handling collision events and triggering CCA

[John Crispin]

On 04.09.20 06:24, Karthikeyan periyasamy wrote:
>> +
>> +static void
>> +hostapd_switch_color_timeout_handler(void *eloop_data, void *user_ctx)
>> +{
>> +    struct hostapd_data *hapd = (struct hostapd_data *) eloop_data;
>> +    struct cca_settings settings;
>> +    struct os_time now;
>> +    int i, r, b, ret;
>> +
>> +    if (os_get_time(&now))
>> +        return;
>> +
>> +    /* check if there has been a recent collision */
>> +    if (now.sec - hapd->last_color_collision.sec >= 10)
>> +        return;
>> +
>
> Why we are dropping CCA when there is no collision for more than 10 secs.
>
> As per the 802.11ax draft 6.0, AP need to wait and see the collision 
> persists for a duration of at least dot11BSSColorCollisionAPPeriod 
> (Default minimum value is 50 seconds).
> in that case, if there is no collision for at least 
> dot11BSSColorCollisionAPPeriod (Default minimum value is 50 seconds) 
> then only we have to drop the CCA. right?
>
>> +    r = os_random() % HE_OPERATION_BSS_COLOR_MAX;
>> +    for (i = 0; i < HE_OPERATION_BSS_COLOR_MAX; i++) {
>> +        if (r && (hapd->color_collision_bitmap & (1 << r)) == 0)
>> +            break;
>> +        r = (r + 1) % HE_OPERATION_BSS_COLOR_MAX;
>> +    }
>> +    if (i == HE_OPERATION_BSS_COLOR_MAX) {
>> +        /* there are no free colors so turn bss coloring off */
>> +        wpa_printf(MSG_INFO, "no free colors left, turning of BSS 
>> coloring");
>> +        hapd->iface->conf->he_op.he_bss_color_disabled = 1;
>> +        hapd->iface->conf->he_op.he_bss_color = 1;
>> +        for (b = 0; b < hapd->iface->num_bss; b++)
>> +            ieee802_11_set_beacon(hapd->iface->bss[b]);
>> +        return;
>> +    }
>> +
>
> Thanks,
> Karthikeyan P.
>
correct, that should be > 50

     John