[121/151] mac80211: Fix dynamic power save for scanning.

Greg KH
2009-12-17T04:17:19Z

From: Vivek Natarajan <vnatarajan@atheros.com>

Upstream commit: 7c3f4bbedc241ddcd3abe1f419c356e625231da1

Not only ps_sdata but also IEEE80211_CONF_PS is to be considered
before restoring PS in scan_ps_disable(). For instance, when ps_sdata
is set but CONF_PS is not set just because the dynamic timer is still
running, a sw scan leads to setting of CONF_PS in scan_ps_disable
instead of restarting the dynamic PS timer.
Also for the above case, a null data frame is to be sent after
returning to operating channel which was not happening with the
current implementation. This patch fixes this too.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/scan.c | 20 ++++++++++++++++----
2 files changed, 17 insertions(+), 4 deletions(-)

--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -808,6 +808,7 @@ struct ieee80211_local {
unsigned int wmm_acm; /* bit field of ACM bits (BIT(802.1D tag)) */

bool pspolling;
+ bool scan_ps_enabled;
/*
* PS can only be enabled when we have exactly one managed
* interface (and monitors) in PS, this then points there.
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -196,7 +196,8 @@ ieee80211_scan_rx(struct ieee80211_sub_i
static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
- bool ps = false;
+
+ local->scan_ps_enabled = false;

/* FIXME: what to do when local->pspolling is true? */

@@ -204,12 +205,13 @@ static void ieee80211_scan_ps_enable(str
cancel_work_sync(&local->dynamic_ps_enable_work);

if (local->hw.conf.flags & IEEE80211_CONF_PS) {
- ps = true;
+ local->scan_ps_enabled = true;
local->hw.conf.flags &= ~IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
}

- if (!ps || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+ if (!(local->scan_ps_enabled) ||
+ !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
/*
* If power save was enabled, no need to send a nullfunc
* frame because AP knows that we are sleeping. But if the
@@ -230,7 +232,7 @@ static void ieee80211_scan_ps_disable(st

if (!local->ps_sdata)
ieee80211_send_nullfunc(local, sdata, 0);
- else {
+ else if (local->scan_ps_enabled) {
/*
* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
* will send a nullfunc frame with the powersave bit set
@@ -246,6 +248,16 @@ static void ieee80211_scan_ps_disable(st
*/
local->hw.conf.flags |= IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+ } else if (local->hw.conf.dynamic_ps_timeout > 0) {
+ /*
+ * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
+ * had been running before leaving the operating channel,
+ * restart the timer now and send a nullfunc frame to inform
+ * the AP that we are awake.
+ */
+ ieee80211_send_nullfunc(local, sdata, 0);
+ mod_timer(&local->dynamic_ps_timer, jiffies +
+ msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
}