Commit 572e0012 authored by Kalle Valo's avatar Kalle Valo Committed by John W. Linville

mac80211: use ps-poll when dynamic power save mode is disabled

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: default avatarKalle Valo <kalle.valo@nokia.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 1fb3606b
......@@ -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,
......
......@@ -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);
}
}
}
......
......@@ -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)
......
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