From 520eb82076993b7f55ef9b80771d264272e5127b Mon Sep 17 00:00:00 2001 From: Kalle Valo Date: Thu, 18 Dec 2008 23:35:27 +0200 Subject: mac80211: implement dynamic power save This patch implements dynamic power save for mac80211. Basically it means enabling power save mode after an idle period. Implementing it dynamically gives a good compromise of low power consumption and low latency. Some hardware have support for this in firmware, but some require the host to do it. The dynamic power save is implemented by adding an timeout to ieee80211_subif_start_xmit(). The timeout can be enabled from userspace with Wireless Extensions. For example, the command below enables the dynamic power save and sets the time timeout to 500 ms: iwconfig wlan0 power timeout 500m Power save now only works with devices which handle power save in firmware. It's also disabled by default and the heuristics when and how to enable is considered as a policy decision and will be left for the userspace to handle. In case the firmware has support for this, drivers can disable this feature with IEEE80211_HW_NO_STACK_DYNAMIC_PS. Big thanks to Johannes Berg for the help with the design and code. Signed-off-by: Kalle Valo Acked-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/wext.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) (limited to 'net/mac80211/wext.c') diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c index f6640d047157..7162d5816f39 100644 --- a/net/mac80211/wext.c +++ b/net/mac80211/wext.c @@ -833,7 +833,7 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev, struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct ieee80211_conf *conf = &local->hw.conf; - int ret = 0; + int ret = 0, timeout = 0; bool ps; if (sdata->vif.type != NL80211_IFTYPE_STATION) @@ -841,6 +841,7 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev, if (wrq->disabled) { ps = false; + timeout = 0; goto set; } @@ -850,22 +851,31 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev, case IW_POWER_ALL_R: /* If explicitely state all */ ps = true; break; - default: /* Otherwise we don't support it */ - return -EINVAL; + default: /* Otherwise we ignore */ + break; } - if (ps == local->powersave) - return ret; + if (wrq->flags & IW_POWER_TIMEOUT) + timeout = wrq->value / 1000; set: + if (ps == local->powersave && timeout == local->dynamic_ps_timeout) + return ret; + local->powersave = ps; + local->dynamic_ps_timeout = timeout; if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) { - if (local->powersave) - conf->flags |= IEEE80211_CONF_PS; - else - conf->flags &= ~IEEE80211_CONF_PS; - + if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) && + local->dynamic_ps_timeout > 0) + mod_timer(&local->dynamic_ps_timer, jiffies + + msecs_to_jiffies(local->dynamic_ps_timeout)); + else { + if (local->powersave) + conf->flags |= IEEE80211_CONF_PS; + else + conf->flags &= ~IEEE80211_CONF_PS; + } ret = ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } -- cgit v1.2.3