p2p: refine random 2.4GHz GO channel selection
2.4GHz channels might be restricted due to cellular coex and
there is no channel availability check after selecting a channel
randomly. When the selected channel is not available, iterate through
other possible 2.4GHz channels until an available channel is found.
Bug: 204409430
Test: start GO on 2.4Ghz band
Change-Id: Ie9a1ed9e3a76f1aa044345aed475ef5061e0632f
diff --git a/wpa_supplicant/p2p_supplicant.c b/wpa_supplicant/p2p_supplicant.c
index 9215794..c68e515 100644
--- a/wpa_supplicant/p2p_supplicant.c
+++ b/wpa_supplicant/p2p_supplicant.c
@@ -6101,7 +6101,25 @@
} else {
if (os_get_random((u8 *) &r, sizeof(r)) < 0)
return -1;
- freq = 2412 + (r % 3) * 25;
+ int possible_2g_freqs[] = {
+ /* operating class 81 */
+ 2412, 2437, 2462,
+ };
+ int possible_2g_freqs_num =
+ sizeof(possible_2g_freqs)/sizeof(possible_2g_freqs[0]);
+ int i;
+ for (i = 0; i < possible_2g_freqs_num; i++, r++) {
+ freq = possible_2g_freqs[r % possible_2g_freqs_num];
+ if (p2p_supported_freq_go(wpa_s->global->p2p, freq)) {
+ break;
+ }
+ }
+
+ if (i >= possible_2g_freqs_num) {
+ wpa_printf(MSG_DEBUG, "P2P: Could not select "
+ "2.4 GHz channel for P2P group");
+ return -1;
+ }
wpa_printf(MSG_DEBUG, "P2P: Use random 2.4 GHz band "
"channel: %d MHz", freq);
}