rtlwifi: Use mutex to replace spin_lock to protect IPS and LPS

Enter/leavel IPS and LPS are large critical section, and they can't use
sleep function because running in atomic-context, which own a spin_lock.
In commit ba9f93f82aba ("rtlwifi: Fix enter/exit power_save"), it moves
LPS functions to thread-context, so this commit can simply change LPS's
spin lock to mutex.
Considering IPS functions, rtl_ips_nic_on() may be called by TX tasklet
(softirq-context) that check whether packet is auth frame. Fortunately,
current mac80211 will ask driver to leave IPS using op_config with
changed flag IEEE80211_CONF_CHANGE_IDLE, before issuing auth frame, so
IPS functions can run in thread-context and use mutex to protect critical
section, too.
Also, this commit removes some useless spin locks.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 10 insertions, 14 deletions

diff --git a/drivers/net/wireless/realtek/rtlwifi/ps.c b/drivers/net/wireless/realtek/rtlwifi/ps.c
index 24c87fae5382..6a4008845f49 100644
--- a/drivers/net/wireless/realtek/rtlwifi/ps.c
+++ b/drivers/net/wireless/realtek/rtlwifi/ps.c
@@ -289,7 +289,7 @@ void rtl_ips_nic_on(struct ieee80211_hw *hw)
 
 	cancel_delayed_work(&rtlpriv->works.ips_nic_off_wq);
 
-	spin_lock(&rtlpriv->locks.ips_lock);
+	mutex_lock(&rtlpriv->locks.ips_mutex);
 	if (ppsc->inactiveps) {
 		rtstate = ppsc->rfpwr_state;
 
@@ -306,7 +306,7 @@ void rtl_ips_nic_on(struct ieee80211_hw *hw)
 									ppsc->inactive_pwrstate);
 		}
 	}
-	spin_unlock(&rtlpriv->locks.ips_lock);
+	mutex_unlock(&rtlpriv->locks.ips_mutex);
 }
 EXPORT_SYMBOL_GPL(rtl_ips_nic_on);
 
@@ -415,7 +415,6 @@ static void rtl_lps_enter_core(struct ieee80211_hw *hw)
 	struct rtl_mac *mac = rtl_mac(rtl_priv(hw));
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw));
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
-	unsigned long flag;
 
 	if (!ppsc->fwctrl_lps)
 		return;
@@ -436,7 +435,7 @@ static void rtl_lps_enter_core(struct ieee80211_hw *hw)
 	if (mac->link_state != MAC80211_LINKED)
 		return;
 
-	spin_lock_irqsave(&rtlpriv->locks.lps_lock, flag);
+	mutex_lock(&rtlpriv->locks.lps_mutex);
 
 	/* Don't need to check (ppsc->dot11_psmode == EACTIVE), because
 	 * bt_ccoexist may ask to enter lps.
@@ -446,7 +445,7 @@ static void rtl_lps_enter_core(struct ieee80211_hw *hw)
 		 "Enter 802.11 power save mode...\n");
 	rtl_lps_set_psmode(hw, EAUTOPS);
 
-	spin_unlock_irqrestore(&rtlpriv->locks.lps_lock, flag);
+	mutex_unlock(&rtlpriv->locks.lps_mutex);
 }
 
 /* Interrupt safe routine to leave the leisure power save mode.*/
@@ -455,9 +454,8 @@ static void rtl_lps_leave_core(struct ieee80211_hw *hw)
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw));
 	struct rtl_hal *rtlhal = rtl_hal(rtl_priv(hw));
-	unsigned long flag;
 
-	spin_lock_irqsave(&rtlpriv->locks.lps_lock, flag);
+	mutex_lock(&rtlpriv->locks.lps_mutex);
 
 	if (ppsc->fwctrl_lps) {
 		if (ppsc->dot11_psmode != EACTIVE) {
@@ -478,7 +476,7 @@ static void rtl_lps_leave_core(struct ieee80211_hw *hw)
 			rtl_lps_set_psmode(hw, EACTIVE);
 		}
 	}
-	spin_unlock_irqrestore(&rtlpriv->locks.lps_lock, flag);
+	mutex_unlock(&rtlpriv->locks.lps_mutex);
 }
 
 /* For sw LPS*/
@@ -568,7 +566,6 @@ void rtl_swlps_rf_awake(struct ieee80211_hw *hw)
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw));
 	struct rtl_mac *mac = rtl_mac(rtl_priv(hw));
-	unsigned long flag;
 
 	if (!rtlpriv->psc.swctrl_lps)
 		return;
@@ -581,9 +578,9 @@ void rtl_swlps_rf_awake(struct ieee80211_hw *hw)
 		RT_CLEAR_PS_LEVEL(ppsc, RT_PS_LEVEL_ASPM);
 	}
 
-	spin_lock_irqsave(&rtlpriv->locks.lps_lock, flag);
+	mutex_lock(&rtlpriv->locks.lps_mutex);
 	rtl_ps_set_rf_state(hw, ERFON, RF_CHANGE_BY_PS);
-	spin_unlock_irqrestore(&rtlpriv->locks.lps_lock, flag);
+	mutex_unlock(&rtlpriv->locks.lps_mutex);
 }
 
 void rtl_swlps_rfon_wq_callback(void *data)
@@ -600,7 +597,6 @@ void rtl_swlps_rf_sleep(struct ieee80211_hw *hw)
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_mac *mac = rtl_mac(rtl_priv(hw));
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw));
-	unsigned long flag;
 	u8 sleep_intv;
 
 	if (!rtlpriv->psc.sw_ps_enabled)
@@ -624,9 +620,9 @@ void rtl_swlps_rf_sleep(struct ieee80211_hw *hw)
 	}
 	spin_unlock(&rtlpriv->locks.rf_ps_lock);
 
-	spin_lock_irqsave(&rtlpriv->locks.lps_lock, flag);
+	mutex_lock(&rtlpriv->locks.lps_mutex);
 	rtl_ps_set_rf_state(hw, ERFSLEEP, RF_CHANGE_BY_PS);
-	spin_unlock_irqrestore(&rtlpriv->locks.lps_lock, flag);
+	mutex_unlock(&rtlpriv->locks.lps_mutex);
 
 	if (ppsc->reg_rfps_level & RT_RF_OFF_LEVL_ASPM &&
 	    !RT_IN_PS_LEVEL(ppsc, RT_PS_LEVEL_ASPM)) {