[PATCH 6/6] staging/rtl8192e,ieee80211: replace ps tasklet with work

[Davidlohr Bueso]

Tasklets have long been deprecated as being too heavy on the system
by running in irq context - and this is not a performance critical
path. If a higher priority process wants to run, it must wait for
the tasklet to finish before doing so.

rtllib_sta_ps() and ieee80211_sta_ps() will now run in process context
and have further concurrency (tasklets being serialized among themselves),
but this is done holding the ieee->lock, so it should be fine.

Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
---
 drivers/staging/rtl8192e/rtllib.h                 |  2 +-
 drivers/staging/rtl8192e/rtllib_rx.c              |  2 +-
 drivers/staging/rtl8192e/rtllib_softmac.c         | 12 ++++++++----
 drivers/staging/rtl8192u/ieee80211/ieee80211.h    |  2 +-
 .../rtl8192u/ieee80211/ieee80211_softmac.c        | 15 +++++++++------
 5 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/rtl8192e/rtllib.h b/drivers/staging/rtl8192e/rtllib.h
index c985e4ebc545..0ecd81a81866 100644
--- a/drivers/staging/rtl8192e/rtllib.h
+++ b/drivers/staging/rtl8192e/rtllib.h
@@ -1585,7 +1585,7 @@ struct rtllib_device {
 	short sta_sleep;
 	int ps_timeout;
 	int ps_period;
-	struct tasklet_struct ps_task;
+	struct work_struct ps_task;
 	u64 ps_time;
 	bool polling;
 
diff --git a/drivers/staging/rtl8192e/rtllib_rx.c b/drivers/staging/rtl8192e/rtllib_rx.c
index eb904b42f9c6..f5a44bc6d4e4 100644
--- a/drivers/staging/rtl8192e/rtllib_rx.c
+++ b/drivers/staging/rtl8192e/rtllib_rx.c
@@ -2721,7 +2721,7 @@ static void rtllib_rx_mgt(struct rtllib_device *ieee,
 		if (ieee->sta_sleep || (ieee->ps != RTLLIB_PS_DISABLED &&
 		    ieee->iw_mode == IW_MODE_INFRA &&
 		    ieee->state == RTLLIB_LINKED))
-			tasklet_schedule(&ieee->ps_task);
+			schedule_work(&ieee->ps_task);
 
 		break;
 
diff --git a/drivers/staging/rtl8192e/rtllib_softmac.c b/drivers/staging/rtl8192e/rtllib_softmac.c
index 4b6c2295a3cf..82bf05eb1cbf 100644
--- a/drivers/staging/rtl8192e/rtllib_softmac.c
+++ b/drivers/staging/rtl8192e/rtllib_softmac.c
@@ -2042,13 +2042,17 @@ static short rtllib_sta_ps_sleep(struct rtllib_device *ieee, u64 *time)
 
 }
 
-static inline void rtllib_sta_ps(struct tasklet_struct *t)
+static inline void rtllib_sta_ps(struct work_struct *work)
 {
-	struct rtllib_device *ieee = from_tasklet(ieee, t, ps_task);
+	struct rtllib_device *ieee;
 	u64 time;
 	short sleep;
 	unsigned long flags, flags2;
 
+	ieee = container_of(work, struct rtllib_device, ps_task);
+	if (!ieee)
+		return;
+
 	spin_lock_irqsave(&ieee->lock, flags);
 
 	if ((ieee->ps == RTLLIB_PS_DISABLED ||
@@ -3028,7 +3032,7 @@ int rtllib_softmac_init(struct rtllib_device *ieee)
 	spin_lock_init(&ieee->mgmt_tx_lock);
 	spin_lock_init(&ieee->beacon_lock);
 
-	tasklet_setup(&ieee->ps_task, rtllib_sta_ps);
+	INIT_WORK(&ieee->ps_task, rtllib_sta_ps);
 
 	return 0;
 }
@@ -3050,8 +3054,8 @@ void rtllib_softmac_free(struct rtllib_device *ieee)
 	cancel_work_sync(&ieee->associate_complete_wq);
 	cancel_work_sync(&ieee->ips_leave_wq);
 	cancel_work_sync(&ieee->wx_sync_scan_wq);
+	cancel_work_sync(&ieee->ps_task);
 	mutex_unlock(&ieee->wx_mutex);
-	tasklet_kill(&ieee->ps_task);
 }
 
 static inline struct sk_buff *
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211.h b/drivers/staging/rtl8192u/ieee80211/ieee80211.h
index 68c0bf9a191a..b577f9c81f85 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211.h
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211.h
@@ -1790,7 +1790,7 @@ struct ieee80211_device {
 	short sta_sleep;
 	int ps_timeout;
 	int ps_period;
-	struct tasklet_struct ps_task;
+	struct work_struct ps_task;
 	u32 ps_th;
 	u32 ps_tl;
 
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
index 1a43979939a8..4e8fbd2410a1 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
@@ -1687,14 +1687,17 @@ static short ieee80211_sta_ps_sleep(struct ieee80211_device *ieee, u32 *time_h,
 	return 1;
 }
 
-static inline void ieee80211_sta_ps(struct tasklet_struct *t)
+static inline void ieee80211_sta_ps(struct work_struct *work)
 {
-	struct ieee80211_device *ieee = from_tasklet(ieee, t, ps_task);
+	struct ieee80211_device *ieee;
 	u32 th, tl;
 	short sleep;
-
 	unsigned long flags, flags2;
 
+	ieee = container_of(work, struct ieee80211_device, ps_task);
+	if (!ieee)
+		return;
+
 	spin_lock_irqsave(&ieee->lock, flags);
 
 	if ((ieee->ps == IEEE80211_PS_DISABLED ||
@@ -1897,7 +1900,7 @@ ieee80211_rx_frame_softmac(struct ieee80211_device *ieee, struct sk_buff *skb,
 	if (ieee->sta_sleep || (ieee->ps != IEEE80211_PS_DISABLED &&
 				ieee->iw_mode == IW_MODE_INFRA &&
 				ieee->state == IEEE80211_LINKED))
-		tasklet_schedule(&ieee->ps_task);
+		schedule_work(&ieee->ps_task);
 
 	if (WLAN_FC_GET_STYPE(header->frame_ctl) != IEEE80211_STYPE_PROBE_RESP &&
 	    WLAN_FC_GET_STYPE(header->frame_ctl) != IEEE80211_STYPE_BEACON)
@@ -2602,7 +2605,7 @@ void ieee80211_softmac_init(struct ieee80211_device *ieee)
 	spin_lock_init(&ieee->mgmt_tx_lock);
 	spin_lock_init(&ieee->beacon_lock);
 
-	tasklet_setup(&ieee->ps_task, ieee80211_sta_ps);
+	INIT_WORK(&ieee->ps_task, ieee80211_sta_ps);
 }
 
 void ieee80211_softmac_free(struct ieee80211_device *ieee)
@@ -2613,7 +2616,7 @@ void ieee80211_softmac_free(struct ieee80211_device *ieee)
 	del_timer_sync(&ieee->associate_timer);
 
 	cancel_delayed_work(&ieee->associate_retry_wq);
-
+	cancel_work_sync(&ieee->ps_task);
 	mutex_unlock(&ieee->wx_mutex);
 }
 
-- 
2.26.2