brcm80211: smac: decreased timer callback irq level

Timer functions were called at soft-irq level, leading to the limitation
that mutexes could not be used. Lifted this limitation by migrating to
work queues.

Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 24 insertions, 28 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
index b665aafe19a..6ce773aee6c 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
@@ -1409,18 +1409,22 @@ void brcms_down(struct brcms_info *wl)
 /*
 * precondition: perimeter lock is not acquired
  */
-void brcms_timer(struct brcms_timer *t)
+static void _brcms_timer(struct work_struct *work)
 {
+        struct brcms_timer *t = container_of(work, struct brcms_timer,
+                                             dly_wrk.work);
+
         spin_lock_bh(&t->wl->lock);
 
         if (t->set) {
                 if (t->periodic) {
-                        t->timer.expires = jiffies + t->ms * HZ / 1000;
                         atomic_inc(&t->wl->callbacks);
-                        add_timer(&t->timer);
-                        t->set = true;
-                } else
+                        ieee80211_queue_delayed_work(t->wl->pub->ieee_hw,
+                                                     &t->dly_wrk,
+                                                     msecs_to_jiffies(t->ms));
+                } else {
                         t->set = false;
+                }
 
                 t->fn(t->arg);
         }
@@ -1431,14 +1435,6 @@ void brcms_timer(struct brcms_timer *t)
 }
 
 /*
- * is called by the kernel from software irq context
- */
-static void _brcms_timer(unsigned long data)
-{
-        brcms_timer((struct brcms_timer *) data);
-}
-
-/*
  * Adds a timer to the list. Caller supplies a timer function.
  * Is called from wlc.
  *
@@ -1454,9 +1450,7 @@ struct brcms_timer *brcms_init_timer(struct brcms_info *wl,
         if (!t)
                 return NULL;
 
-        init_timer(&t->timer);
-        t->timer.data = (unsigned long) t;
-        t->timer.function = _brcms_timer;
+        INIT_DELAYED_WORK(&t->dly_wrk, _brcms_timer);
         t->wl = wl;
         t->fn = fn;
         t->arg = arg;
@@ -1478,22 +1472,22 @@ struct brcms_timer *brcms_init_timer(struct brcms_info *wl,
  *
  * precondition: perimeter lock has been acquired
  */
-void brcms_add_timer(struct brcms_timer *t, uint ms,
-                     int periodic)
+void brcms_add_timer(struct brcms_timer *t, uint ms, int periodic)
 {
+        struct ieee80211_hw *hw = t->wl->pub->ieee_hw;
+
 #ifdef BCMDBG
         if (t->set)
-                wiphy_err(t->wl->wiphy, "%s: Already set. Name: %s, per %d\n",
+                wiphy_err(hw->wiphy, "%s: Already set. Name: %s, per %d\n",
                           __func__, t->name, periodic);
-
 #endif
         t->ms = ms;
         t->periodic = (bool) periodic;
         t->set = true;
-        t->timer.expires = jiffies + ms * HZ / 1000;
 
         atomic_inc(&t->wl->callbacks);
-        add_timer(&t->timer);
+
+        ieee80211_queue_delayed_work(hw, &t->dly_wrk, msecs_to_jiffies(ms));
 }
 
 /*
@@ -1505,7 +1499,7 @@ bool brcms_del_timer(struct brcms_timer *t)
 {
         if (t->set) {
                 t->set = false;
-                if (!del_timer(&t->timer))
+                if (!cancel_delayed_work(&t->dly_wrk))
                         return false;
 
                 atomic_dec(&t->wl->callbacks);
diff --git a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
index 91e5f2ac56c..177f0e44e4b 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
+++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
@@ -19,6 +19,8 @@
 
 #include <linux/timer.h>
 #include <linux/interrupt.h>
+#include <linux/workqueue.h>
+
 #include "ucode_loader.h"
 /*
  * Starting index for 5G rates in the
@@ -30,14 +32,14 @@
 #define BRCMS_SET_SHORTSLOT_OVERRIDE            146
 
 struct brcms_timer {
-        struct timer_list timer;
+        struct delayed_work dly_wrk;
         struct brcms_info *wl;
-        void (*fn) (void *);
-        void *arg;              /* argument to fn */
+        void (*fn) (void *);    /* function called upon expiration */
+        void *arg;              /* fixed argument provided to called function */
         uint ms;
         bool periodic;
-        bool set;
-        struct brcms_timer *next;
+        bool set;               /* indicates if timer is active */
+        struct brcms_timer *next;       /* for freeing on unload */
 #ifdef BCMDBG
         char *name;             /* Description of the timer */
 #endif