The following patch proposes an implementation to handle WLAN-Bluetooth
coexistence in the case of a shared WLAN/BT antenna.
The patch adds to mac80211 an interface for the driver to be able to
temporarily disable dynamic power save. When power save is enabled, a call to
the function will cause mac80211 to immediately enter full PSM until the driver
indicates that dynamic PSM can be resumed. If power save is enabled the
function does nothing.
The driver uses this function to disable dynamic PSM whenever there are bursts
Bluetooth traffic. Full PSM allows the WLAN hardware to relinquish the antenna
for use by BT during the inactive WLAN periods.
The driver gets information on Bluetooth traffic from the WLAN chipset. The
chipset has hardware lines to coordinate the co-existence, and the chipset will
indicate to the driver whenever there is Bluetooth traffic.
Comments are welcomed!
Juuso Oikarinen (1):
mac80211: Add interface for driver to temporarily disable dynamic ps
include/net/mac80211.h | 15 +++++++++++++++
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/iface.c | 1 +
net/mac80211/mlme.c | 20 +++++++++++++++++++-
net/mac80211/rx.c | 3 ++-
net/mac80211/tx.c | 4 ++++
6 files changed, 44 insertions(+), 2 deletions(-)
For devices with a shared WLAN/BT antenna, managing WLAN co-existence with
Bluetooth requires WLAN full power save whenever there is Bluetooth activity in
order for WLAN to be able to periodically relinquish the antenna to be used
for BT.
BT traffic is often temporary in nature, hence disabling dynamic power save
fully whenever BT unnecessary reduces WLAN performance.
The hardware gets information of Bluetooth traffic via hardware co-existence
control lines, and based on those lines, the hardware requests, via the
WLAN driver, mac80211 to disable dynamic PS for the duration of the burst.
This patch add the interface to mac80211 to facilitate temporarily disabling
dynamic power save as per request of the WLAN driver. This interface will not
change PSM state, if PSM is disabled it will remain so.
Signed-off-by: Juuso Oikarinen <[email protected]>
---
include/net/mac80211.h | 15 +++++++++++++++
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/iface.c | 1 +
net/mac80211/mlme.c | 20 +++++++++++++++++++-
net/mac80211/rx.c | 3 ++-
net/mac80211/tx.c | 4 ++++
6 files changed, 44 insertions(+), 2 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index de22cbf..e4a97ea 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2460,6 +2460,21 @@ void ieee80211_beacon_loss(struct ieee80211_vif *vif);
void ieee80211_connection_loss(struct ieee80211_vif *vif);
/**
+ * ieee80211_disable_dyn_ps - force mac80211 to temporarily disable dynamic psm
+ *
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * Some hardware require full power save to manage simultaneous BT traffic
+ * on the WLAN frequency. Full PSM is required periodically, whenever there are
+ * burst of BT traffic. The hardware gets information of BT traffic via
+ * hardware co-existence lines, and consequentially requests mac80211 to
+ * (temporarily) enter full psm.
+ * This function will only temporarily disable dynamic PS, not enable PSM if
+ * it was not already enabled.
+ */
+void ieee80211_disable_dyn_ps(struct ieee80211_vif *vif, bool disable);
+
+/**
* ieee80211_cqm_rssi_notify - inform a configured connection quality monitoring
* rssi threshold triggered
*
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1a9e2da..cab32c7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -505,6 +505,9 @@ struct ieee80211_sub_if_data {
*/
bool ht_opmode_valid;
+ /* dynamic powersave temporarily disabled by driver */
+ bool disable_dyn_ps;
+
/* Fragment table for host-based reassembly */
struct ieee80211_fragment_entry fragments[IEEE80211_FRAGMENT_MAX];
unsigned int fragment_next;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 50deb01..ac2b8a5 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -421,6 +421,7 @@ static int ieee80211_stop(struct net_device *dev)
del_timer_sync(&local->dynamic_ps_timer);
cancel_work_sync(&local->dynamic_ps_enable_work);
+ sdata->disable_dyn_ps = false;
/* APs need special treatment */
if (sdata->vif.type == NL80211_IFTYPE_AP) {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 0839c4e..aaa86ee 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -478,6 +478,24 @@ static void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
}
}
+void ieee80211_disable_dyn_ps(struct ieee80211_vif *vif, bool disable)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+
+ WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION);
+
+ sdata->disable_dyn_ps = disable;
+
+ /* immediately go to psm */
+ if (disable && timer_pending(&local->dynamic_ps_timer)) {
+ ieee80211_queue_work(&local->hw,
+ &local->dynamic_ps_enable_work);
+ del_timer_sync(&local->dynamic_ps_timer);
+ }
+}
+EXPORT_SYMBOL(ieee80211_disable_dyn_ps);
+
/* powersave */
static void ieee80211_enable_ps(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata)
@@ -491,7 +509,7 @@ static void ieee80211_enable_ps(struct ieee80211_local *local,
if (local->scanning)
return;
- if (conf->dynamic_ps_timeout > 0 &&
+ if (conf->dynamic_ps_timeout > 0 && !sdata->disable_dyn_ps &&
!(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)) {
mod_timer(&local->dynamic_ps_timer, jiffies +
msecs_to_jiffies(conf->dynamic_ps_timeout));
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6e2a7bc..e11d52b 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1793,7 +1793,8 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
if (ieee80211_is_data(hdr->frame_control) &&
!is_multicast_ether_addr(hdr->addr1) &&
- local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
+ local->hw.conf.dynamic_ps_timeout > 0 && !sdata->disable_dyn_ps &&
+ local->ps_sdata) {
mod_timer(&local->dynamic_ps_timer, jiffies +
msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 680bcb7..6f6b046 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -194,6 +194,10 @@ ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
return TX_CONTINUE;
+ /* dynamic PS has not been temporarily disabled by driver */
+ if (tx->sdata->disable_dyn_ps)
+ return TX_CONTINUE;
+
/* dynamic power save disabled */
if (local->hw.conf.dynamic_ps_timeout <= 0)
return TX_CONTINUE;
--
1.6.3.3