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 again. 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. Power save mode is not disabled
during ps-polling, the assumption is that firmware still receives
responses to the ps-poll frame.
Using ps-poll is slower than waking up with null frame, but I
recommend using dynamic power save in cases where throughput is
important. User space can enable it with 'iwconfig wlan0 power timeout
<value>'.
Signed-off-by: Kalle Valo <kalle.valo@xxxxxx>
---
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/mlme.c | 40 +++++++++++++++++++++++++++++++++++++---
net/mac80211/rx.c | 35 +++++++++++++++++++++++++++++++++++
3 files changed, 75 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c9ffadb..76814e9 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -710,6 +710,7 @@ 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;
@@ -902,6 +903,8 @@ u64 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 c7e61e2..c8778f3 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -475,6 +475,41 @@ 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;
+ 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);
+
+ printk(KERN_DEBUG "sending ps-poll");
+
+ 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)
@@ -1816,9 +1851,8 @@ 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);
+ local->pspolling = true;
+ ieee80211_send_pspoll(local, sdata);
}
}
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 9fd9d21..7d24dde 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -740,6 +740,40 @@ 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 */
+ printk(KERN_DEBUG "no more data");
+ 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 0;
+}
+
static void ap_sta_ps_start(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
@@ -2006,6 +2040,7 @@ 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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