Return-path: Received: from smtp.nokia.com ([192.100.122.230]:38655 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751837AbZBJPKa (ORCPT ); Tue, 10 Feb 2009 10:10:30 -0500 From: Kalle Valo Subject: [PATCH v4 2/2] mac80211: use ps-poll when dynamic power save mode is disabled To: linville@tuxdriver.com Cc: linux-wireless@vger.kernel.org, johannes@sipsolutions.net, vivek.natraj@gmail.com Date: Tue, 10 Feb 2009 17:09:31 +0200 Message-ID: <20090210150931.21245.52052.stgit@tikku> (sfid-20090210_161032_919459_5CD0FF85) In-Reply-To: <20090210150822.21245.87099.stgit@tikku> References: <20090210150822.21245.87099.stgit@tikku> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: When a directed tim bit is set, mac80211 currently disables power save ands sends a null frame to the AP. But if dynamic power save is disabled, mac80211 will not enable power save ever gain. Fix this by adding ps-poll functionality to mac80211. When a directed tim bit is set, mac80211 sends a ps-poll frame to the AP and checks for the more data bit in the returned data frames. Using ps-poll is slower than waking up with null frame, but it's saves more power in cases where the traffic is low. Userspace can control if either ps-poll or null wakeup method is used by enabling and disabling dynamic power save. Signed-off-by: Kalle Valo --- net/mac80211/ieee80211_i.h | 3 ++ net/mac80211/mlme.c | 54 ++++++++++++++++++++++++++++++++++++++++++-- net/mac80211/rx.c | 34 ++++++++++++++++++++++++++++ 3 files changed, 88 insertions(+), 3 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 5a1f19a..67bd522 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -728,6 +728,7 @@ struct ieee80211_local { unsigned int wmm_acm; /* bit field of ACM bits (BIT(802.1D tag)) */ bool powersave; + bool pspolling; struct work_struct dynamic_ps_enable_work; struct work_struct dynamic_ps_disable_work; struct timer_list dynamic_ps_timer; @@ -921,6 +922,8 @@ u32 ieee80211_sta_get_rates(struct ieee80211_local *local, enum ieee80211_band band); void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, u8 *ssid, size_t ssid_len); +void ieee80211_send_pspoll(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata); /* scan/BSS handling */ int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 05c8d13..169f10c 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -511,6 +511,39 @@ static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata, ieee80211_tx_skb(sdata, skb, ifsta->flags & IEEE80211_STA_MFP_ENABLED); } +void ieee80211_send_pspoll(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct ieee80211_pspoll *pspoll; + struct sk_buff *skb; + u16 fc; + + skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll)); + if (!skb) { + printk(KERN_DEBUG "%s: failed to allocate buffer for " + "pspoll frame\n", sdata->dev->name); + return; + } + skb_reserve(skb, local->hw.extra_tx_headroom); + + pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll)); + memset(pspoll, 0, sizeof(*pspoll)); + fc = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_PSPOLL | IEEE80211_FCTL_PM; + pspoll->frame_control = cpu_to_le16(fc); + pspoll->aid = cpu_to_le16(ifsta->aid); + + /* aid in PS-Poll has its two MSBs each set to 1 */ + pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14); + + memcpy(pspoll->bssid, ifsta->bssid, ETH_ALEN); + memcpy(pspoll->ta, sdata->dev->dev_addr, ETH_ALEN); + + ieee80211_tx_skb(sdata, skb, 0); + + return; +} + /* MLME */ static void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata, struct ieee80211_bss *bss) @@ -1868,9 +1901,24 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, directed_tim = ieee80211_check_tim(&elems, ifsta->aid); if (directed_tim) { - local->hw.conf.flags &= ~IEEE80211_CONF_PS; - ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); - ieee80211_send_nullfunc(local, sdata, 0); + if (local->hw.conf.dynamic_ps_timeout > 0) { + local->hw.conf.flags &= ~IEEE80211_CONF_PS; + ieee80211_hw_config(local, + IEEE80211_CONF_CHANGE_PS); + ieee80211_send_nullfunc(local, sdata, 0); + } else { + local->pspolling = true; + + /* + * Here is assumed that the driver will be + * able to send ps-poll frame and receive a + * response even though power save mode is + * enabled, but some drivers might require + * to disable power save here. This needs + * to be investigated. + */ + ieee80211_send_pspoll(local, sdata); + } } } diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 8e8ddbf..0e030d3 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -731,6 +731,39 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) return result; } +static ieee80211_rx_result debug_noinline +ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx) +{ + struct ieee80211_local *local; + struct ieee80211_hdr *hdr; + struct sk_buff *skb; + + local = rx->local; + skb = rx->skb; + hdr = (struct ieee80211_hdr *) skb->data; + + if (!local->pspolling) + return RX_CONTINUE; + + if (!ieee80211_has_fromds(hdr->frame_control)) + /* this is not from AP */ + return RX_CONTINUE; + + if (!ieee80211_is_data(hdr->frame_control)) + return RX_CONTINUE; + + if (!ieee80211_has_moredata(hdr->frame_control)) { + /* AP has no more frames buffered for us */ + local->pspolling = false; + return RX_CONTINUE; + } + + /* more data bit is set, let's request a new frame from the AP */ + ieee80211_send_pspoll(local, rx->sdata); + + return RX_CONTINUE; +} + static void ap_sta_ps_start(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; @@ -1987,6 +2020,7 @@ static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata, CALL_RXH(ieee80211_rx_h_passive_scan) CALL_RXH(ieee80211_rx_h_check) CALL_RXH(ieee80211_rx_h_decrypt) + CALL_RXH(ieee80211_rx_h_check_more_data) CALL_RXH(ieee80211_rx_h_sta_process) CALL_RXH(ieee80211_rx_h_defragment) CALL_RXH(ieee80211_rx_h_ps_poll)