From: Irfan Sheriff <isheriff@google.com>
Date: Wed, 17 Oct 2012 04:40:46 +0000 (-0700)
Subject: Increase channel delay to 100ms
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8fb4647b1a7a730366d57c0fc2894b0069840167;p=thirdparty%2Fhostap.git

Increase channel delay to 100ms

There is an inherent flaw in the p2p protocol design where an ACK loss right
before channel switch leads to peers being out of sync.

A work around of 50ms was added persistent case, but it turns out in heavy lossy
conditions that is not enough. Increase it to 100ms.

Experimental evaluation showed 100ms improves the reliability of p2p persistence
reinvocation.

Bug: 7359500
Change-Id: I73ab1b64e32b87101e95b0e487c90818c2c0aaf3
---

diff --git a/wpa_supplicant/p2p_supplicant.c b/wpa_supplicant/p2p_supplicant.c
index 6271425a0..e71f3fd67 100644
--- a/wpa_supplicant/p2p_supplicant.c
+++ b/wpa_supplicant/p2p_supplicant.c
@@ -3433,9 +3433,15 @@ static void wpas_invitation_result(void *ctx, int status, const u8 *bssid,
 	 * the persistent group so that we will remain on the current channel to
 	 * acknowledge any possible retransmission from the peer.
 	 */
+#ifndef ANDROID_P2P
 	wpa_dbg(wpa_s, MSG_DEBUG, "P2P: 50 ms wait on current channel before "
 		"starting persistent group");
 	os_sleep(0, 50000);
+#else
+	wpa_dbg(wpa_s, MSG_DEBUG, "P2P: 100 ms wait on current channel before "
+		"starting persistent group");
+	os_sleep(0, 100000);
+#endif
 
 	if (neg_freq > 0 && ssid->mode == WPAS_MODE_P2P_GO &&
 	    freq_included(channels, neg_freq))