Hi Jahannes, All, I'm trying to get our WiFi driver to get power save notifications from the mac80211. For this I have set the below flags: ieee80211_hw_set(hw, SUPPORTS_PS); ieee80211_hw_set(hw, PS_NULLFUNC_STACK); My tracing shows that, once power save is enabled, we get a QoS NULL Function packet. mac80211 is then waiting for the ACK confirmation of the packet. However even when this ACK is received (in the tx_status), no change notification is sent to the driver. The code below (in __ieee80211_tx_status), indicates that we set the IEEE80211_STA_NULLFUNC_ACKED flag (for the managed interface), yet we don't invoke ieee80211_dynamic_ps_enable_work (to notify the change of PS state). should we be calling the dynamic_ps_timer again or am I missing something? if (ieee80211_is_any_nullfunc(fc) && ieee80211_has_pm(fc) && ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) && !(info->flags & IEEE80211_TX_CTL_INJECTED) && local->ps_sdata && !(local->scanning)) { if (info->flags & IEEE80211_TX_STAT_ACK) { local->ps_sdata->u.mgd.flags |= IEEE80211_STA_NULLFUNC_ACKED; } else mod_timer(&local->dynamic_ps_timer, jiffies + msecs_to_jiffies(10)); } } Thanks Bassem