ACS: Extend acs_find_ideal_chan() to support multiple modes

This is preparation for being able to support hw_mode=any to select the
best channel from any supported mode.

Signed-off-by: Neo Jou <neojou@gmail.com>

diff --git a/src/ap/acs.c b/src/ap/acs.c
index 7357a41548637837ba4f047dc6b50c982c2d88bc..ecd42d8775612762faf5615e33ff62c4db8be8de 100644 (file)
--- a/src/ap/acs.c
+++ b/src/ap/acs.c
@@ -622,58 +622,24 @@ static int is_common_24ghz_chan(int chan)
 #define ACS_24GHZ_PREFER_1_6_11 0.8
 #endif /* ACS_24GHZ_PREFER_1_6_11 */
 
-/*
- * At this point it's assumed chan->interference_factor has been computed.
- * This function should be reusable regardless of interference computation
- * option (survey, BSS, spectral, ...). chan->interference factor must be
- * summable (i.e., must be always greater than zero).
- */
-static struct hostapd_channel_data *
-acs_find_ideal_chan(struct hostapd_iface *iface)
+static void
+acs_find_ideal_chan_mode(struct hostapd_iface *iface,
+                        struct hostapd_hw_modes *mode,
+                        int n_chans, u32 bw,
+                        struct hostapd_channel_data **rand_chan,
+                        struct hostapd_channel_data **ideal_chan,
+                        long double *ideal_factor)
 {
-       struct hostapd_channel_data *chan, *adj_chan, *ideal_chan = NULL,
-               *rand_chan = NULL;
-       long double factor, ideal_factor = 0;
+       struct hostapd_channel_data *chan, *adj_chan = NULL;
+       long double factor;
        int i, j;
-       int n_chans = 1;
-       u32 bw;
        unsigned int k;
 
-       /* TODO: HT40- support */
-
-       if (iface->conf->ieee80211n &&
-           iface->conf->secondary_channel == -1) {
-               wpa_printf(MSG_ERROR, "ACS: HT40- is not supported yet. Please try HT40+");
-               return NULL;
-       }
-
-       if (iface->conf->ieee80211n &&
-           iface->conf->secondary_channel)
-               n_chans = 2;
-
-       if (iface->conf->ieee80211ac || iface->conf->ieee80211ax) {
-               switch (hostapd_get_oper_chwidth(iface->conf)) {
-               case CHANWIDTH_80MHZ:
-                       n_chans = 4;
-                       break;
-               case CHANWIDTH_160MHZ:
-                       n_chans = 8;
-                       break;
-               }
-       }
-
-       bw = num_chan_to_bw(n_chans);
-
-       /* TODO: VHT/HE80+80. Update acs_adjust_center_freq() too. */
-
-       wpa_printf(MSG_DEBUG,
-                  "ACS: Survey analysis for selected bandwidth %d MHz", bw);
-
-       for (i = 0; i < iface->current_mode->num_channels; i++) {
+       for (i = 0; i < mode->num_channels; i++) {
                double total_weight;
                struct acs_bias *bias, tmp_bias;
 
-               chan = &iface->current_mode->channels[i];
+               chan = &mode->channels[i];
 
                /* Since in the current ACS implementation the first channel is
                 * always a primary channel, skip channels not available as
@@ -694,7 +660,7 @@ acs_find_ideal_chan(struct hostapd_iface *iface)
 
                /* HT40 on 5 GHz has a limited set of primary channels as per
                 * 11n Annex J */
-               if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A &&
+               if (mode->mode == HOSTAPD_MODE_IEEE80211A &&
                    iface->conf->ieee80211n &&
                    iface->conf->secondary_channel &&
                    !acs_usable_ht40_chan(chan)) {
@@ -703,7 +669,7 @@ acs_find_ideal_chan(struct hostapd_iface *iface)
                        continue;
                }
 
-               if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A &&
+               if (mode->mode == HOSTAPD_MODE_IEEE80211A &&
                    (iface->conf->ieee80211ac || iface->conf->ieee80211ax)) {
                        if (hostapd_get_oper_chwidth(iface->conf) ==
                            CHANWIDTH_80MHZ &&
@@ -755,7 +721,7 @@ acs_find_ideal_chan(struct hostapd_iface *iface)
 
                /* 2.4 GHz has overlapping 20 MHz channels. Include adjacent
                 * channel interference factor. */
-               if (is_24ghz_mode(iface->current_mode->mode)) {
+               if (is_24ghz_mode(mode->mode)) {
                        for (j = 0; j < n_chans; j++) {
                                adj_chan = acs_find_chan(iface, chan->freq +
                                                         (j * 20) - 5);
@@ -801,7 +767,7 @@ acs_find_ideal_chan(struct hostapd_iface *iface)
                                        break;
                                bias = NULL;
                        }
-               } else if (is_24ghz_mode(iface->current_mode->mode) &&
+               } else if (is_24ghz_mode(mode->mode) &&
                           is_common_24ghz_chan(chan->chan)) {
                        tmp_bias.channel = chan->chan;
                        tmp_bias.bias = ACS_24GHZ_PREFER_1_6_11;
@@ -820,14 +786,71 @@ acs_find_ideal_chan(struct hostapd_iface *iface)
                }
 
                if (acs_usable_chan(chan) &&
-                   (!ideal_chan || factor < ideal_factor)) {
-                       ideal_factor = factor;
-                       ideal_chan = chan;
+                   (!*ideal_chan || factor < *ideal_factor)) {
+                       *ideal_factor = factor;
+                       *ideal_chan = chan;
                }
 
                /* This channel would at least be usable */
-               if (!rand_chan)
-                       rand_chan = chan;
+               if (!(*rand_chan))
+                       *rand_chan = chan;
+       }
+}
+
+
+/*
+ * At this point it's assumed chan->interference_factor has been computed.
+ * This function should be reusable regardless of interference computation
+ * option (survey, BSS, spectral, ...). chan->interference factor must be
+ * summable (i.e., must be always greater than zero).
+ */
+static struct hostapd_channel_data *
+acs_find_ideal_chan(struct hostapd_iface *iface)
+{
+       struct hostapd_channel_data *ideal_chan = NULL,
+               *rand_chan = NULL;
+       long double ideal_factor = 0;
+       int i;
+       int n_chans = 1;
+       u32 bw;
+       struct hostapd_hw_modes *mode;
+
+       /* TODO: HT40- support */
+
+       if (iface->conf->ieee80211n &&
+           iface->conf->secondary_channel == -1) {
+               wpa_printf(MSG_ERROR, "ACS: HT40- is not supported yet. Please try HT40+");
+               return NULL;
+       }
+
+       if (iface->conf->ieee80211n &&
+           iface->conf->secondary_channel)
+               n_chans = 2;
+
+       if (iface->conf->ieee80211ac || iface->conf->ieee80211ax) {
+               switch (hostapd_get_oper_chwidth(iface->conf)) {
+               case CHANWIDTH_80MHZ:
+                       n_chans = 4;
+                       break;
+               case CHANWIDTH_160MHZ:
+                       n_chans = 8;
+                       break;
+               }
+       }
+
+       bw = num_chan_to_bw(n_chans);
+
+       /* TODO: VHT/HE80+80. Update acs_adjust_center_freq() too. */
+
+       wpa_printf(MSG_DEBUG,
+                  "ACS: Survey analysis for selected bandwidth %d MHz", bw);
+
+       for (i = 0; i < iface->num_hw_features; i++) {
+               mode = &iface->hw_features[i];
+               if (!hostapd_hw_skip_mode(iface, mode))
+                       acs_find_ideal_chan_mode(iface, mode, n_chans, bw,
+                                                &rand_chan, &ideal_chan,
+                                                &ideal_factor);
        }
 
        if (ideal_chan) {