Return-path: Received: from smtp-out.google.com ([216.239.44.51]:38214 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753561Ab0JMWsx (ORCPT ); Wed, 13 Oct 2010 18:48:53 -0400 Received: from kpbe12.cbf.corp.google.com (kpbe12.cbf.corp.google.com [172.25.105.76]) by smtp-out.google.com with ESMTP id o9DMmqK5022921 for ; Wed, 13 Oct 2010 15:48:53 -0700 Received: from glenhelen.mtv.corp.google.com (glenhelen.mtv.corp.google.com [172.22.72.223]) by kpbe12.cbf.corp.google.com with ESMTP id o9DMmpPK020047 for ; Wed, 13 Oct 2010 15:48:52 -0700 From: Paul Stewart Date: Wed, 13 Oct 2010 15:13:50 -0700 Subject: [PATCH 3/6] Add a function for evaluating rate changes for possible notification To: linux-wireless@vger.kernel.org Message-Id: <20101013224851.B8E5D20465@glenhelen.mtv.corp.google.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Called from a work proc, this examines the last transmit rate change to see if it warrants an event transmission. Signed-off-by: Paul Stewart --- net/mac80211/rate.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++ net/mac80211/rate.h | 8 +++++ 2 files changed, 82 insertions(+), 0 deletions(-) diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c index 4f772de..5e39494 100644 --- a/net/mac80211/rate.c +++ b/net/mac80211/rate.c @@ -399,3 +399,77 @@ void rate_control_deinitialize(struct ieee80211_local *local) rate_control_put(ref); } +u32 ieee80211_rate_calculate(struct ieee80211_local *local, + struct ieee80211_if_managed *ifmgd) +{ + u32 rate_val; + u32 modulation, streams, base_rate, mcs, gi_div; + struct ieee80211_tx_rate *rate_ptr = &ifmgd->last_cqm_tx_rate; + struct ieee80211_supported_band *sband; + static int mod_table[8] = { 1, 2, 3, 4, 6, 8, 9, 10 }; + + if (!(rate_ptr->flags & IEEE80211_TX_RC_MCS)) { + sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; + return sband->bitrates[ifmgd->last_cqm_tx_rate.idx].bitrate; + } + + mcs = rate_ptr->idx; + + /* MCS values over 32 are not yet supported */ + if (mcs >= 32) + return 0; + + modulation = mcs & 7; + streams = (mcs >> 3) + 1; + base_rate = (rate_ptr->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) ? + 13500000 : 6500000; + gi_div = (rate_ptr->flags & IEEE80211_TX_RC_SHORT_GI) ? 9 : 10; + rate_val = base_rate * mod_table[modulation] * streams / gi_div; + + return ((rate_val + 5000) / 10000) * 100; +} + +void ieee80211_cqm_bitrate_notify(struct ieee80211_local *local) +{ + struct ieee80211_sub_if_data *sdata; + struct ieee80211_if_managed *ifmgd; + struct ieee80211_bss_conf *bss_conf; + u32 bitrate, threshold; + int prev_state, new_state; + + WARN_ON(!mutex_is_locked(&local->iflist_mtx)); + + list_for_each_entry(sdata, &local->interfaces, list) { + if (!netif_running(sdata->dev) || + sdata->vif.type != NL80211_IFTYPE_STATION) + continue; + + ifmgd = &sdata->u.mgd; + bss_conf = &sdata->vif.bss_conf; + + if (!(ifmgd->flags & IEEE80211_STA_TX_RATE_CHANGED) || + bss_conf->cqm_bitrate_thold == 0) + continue; + + bitrate = ieee80211_rate_calculate(local, ifmgd); + threshold = bss_conf->cqm_bitrate_thold; + prev_state = (ifmgd->last_cqm_bitrate < threshold); + new_state = (bitrate < threshold); + + /* + * Trigger a bitrate notification if one of the following is + * true: + * - We haven't sent one since the threshold was reconfigured + * - We have crossed the threshold in either direction + * - We are below threshold, and the bitrate has decreased yet + * again. + */ + if (ifmgd->last_cqm_bitrate == 0 || prev_state != new_state || + (new_state && bitrate < ifmgd->last_cqm_bitrate)) { + cfg80211_cqm_bitrate_notify(sdata->dev, bitrate, + GFP_KERNEL); + ifmgd->last_cqm_bitrate = bitrate; + } + ifmgd->flags &= ~IEEE80211_STA_TX_RATE_CHANGED; + } +} diff --git a/net/mac80211/rate.h b/net/mac80211/rate.h index 168427b..33e4ca3 100644 --- a/net/mac80211/rate.h +++ b/net/mac80211/rate.h @@ -120,6 +120,14 @@ int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, void rate_control_deinitialize(struct ieee80211_local *local); +/* Notify listeners about transmit rate changes */ +void ieee80211_cqm_bitrate_notify(struct ieee80211_local *local); + +/* Convert rate into cfg80211-compatible struct? */ +void ieee80211_rate_convert_cfg(struct ieee80211_local *local, + struct ieee80211_if_managed *ifmgd, + struct rate_info *rate); + /* Rate control algorithms */ #ifdef CONFIG_MAC80211_RC_PID extern int rc80211_pid_init(void); -- 1.7.1