Revert "timers: Rename del_timer_sync() to timer_delete_sync()"

This reverts commit 48a8a53 which is
commit 9b13df3fb64ee95e2397585404e442afee2c7d4f upstream.

It breaks the Android kernel abi by turning del_timer_sync() into an
inline function, which breaks the abi.  Fix this by putting it back as
needed AND fix up the only use of this new function in
drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c which is
what caused this commit to be backported to 4.19.y in the first place.

Bug: 161946584
Change-Id: Icd26c7c81e6172f36eeeb69827989bfab1d32afe
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Author: gregkh

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

@@ -690,7 +690,7 @@ s32 brcmf_notify_escan_complete(struct brcmf_cfg80211_info *cfg,
 	scan_request = cfg->scan_request;
 	cfg->scan_request = NULL;
 
-	timer_delete_sync(&cfg->escan_timeout);
+	del_timer_sync(&cfg->escan_timeout);
 
 	if (fw_abort) {
 		/* Do a scan abort to stop the driver's scan engine */

include/linux/timer.h

@@ -175,20 +175,7 @@ extern int timer_reduce(struct timer_list *timer, unsigned long expires);
 extern void add_timer(struct timer_list *timer);
 
 extern int try_to_del_timer_sync(struct timer_list *timer);
-extern int timer_delete_sync(struct timer_list *timer);
-
-/**
- * del_timer_sync - Delete a pending timer and wait for a running callback
- * @timer:	The timer to be deleted
- *
- * See timer_delete_sync() for detailed explanation.
- *
- * Do not use in new code. Use timer_delete_sync() instead.
- */
-static inline int del_timer_sync(struct timer_list *timer)
-{
-	return timer_delete_sync(timer);
-}
+extern int del_timer_sync(struct timer_list *timer);
 
 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 

kernel/time/timer.c

@@ -1037,7 +1037,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int option
 		/*
 		 * We are trying to schedule the timer on the new base.
 		 * However we can't change timer's base while it is running,
-		 * otherwise timer_delete_sync() can't detect that the timer's
+		 * otherwise del_timer_sync() can't detect that the timer's
 		 * handler yet has not finished. This also guarantees that the
 		 * timer is serialized wrt itself.
 		 */
@@ -1216,7 +1216,7 @@ EXPORT_SYMBOL_GPL(add_timer_on);
  * @timer:	The timer to be deactivated
  *
  * The function only deactivates a pending timer, but contrary to
- * timer_delete_sync() it does not take into account whether the timer's
+ * del_timer_sync() it does not take into account whether the timer's
  * callback function is concurrently executed on a different CPU or not.
  * It neither prevents rearming of the timer. If @timer can be rearmed
  * concurrently then the return value of this function is meaningless.
@@ -1350,7 +1350,7 @@ static inline void del_timer_wait_running(struct timer_list *timer) { }
 #endif
 
 /**
- * timer_delete_sync - Deactivate a timer and wait for the handler to finish.
+ * del_timer_sync - Deactivate a timer and wait for the handler to finish.
  * @timer:	The timer to be deactivated
  *
  * Synchronization rules: Callers must prevent restarting of the timer,
@@ -1372,10 +1372,10 @@ static inline void del_timer_wait_running(struct timer_list *timer) { }
  *    spin_lock_irq(somelock);
  *                                     <IRQ>
  *                                        spin_lock(somelock);
- *    timer_delete_sync(mytimer);
+ *    del_timer_sync(mytimer);
  *    while (base->running_timer == mytimer);
  *
- * Now timer_delete_sync() will never return and never release somelock.
+ * Now del_timer_sync() will never return and never release somelock.
  * The interrupt on the other CPU is waiting to grab somelock but it has
  * interrupted the softirq that CPU0 is waiting to finish.
  *
@@ -1388,7 +1388,7 @@ static inline void del_timer_wait_running(struct timer_list *timer) { }
  * * %0	- The timer was not pending
  * * %1	- The timer was pending and deactivated
  */
-int timer_delete_sync(struct timer_list *timer)
+int del_timer_sync(struct timer_list *timer)
 {
 	int ret;
 
@@ -1421,7 +1421,7 @@ int timer_delete_sync(struct timer_list *timer)
 
 	return ret;
 }
-EXPORT_SYMBOL(timer_delete_sync);
+EXPORT_SYMBOL(del_timer_sync);
 
 static void call_timer_fn(struct timer_list *timer,
 			  void (*fn)(struct timer_list *),
@@ -1443,8 +1443,8 @@ static void call_timer_fn(struct timer_list *timer,
 #endif
 	/*
 	 * Couple the lock chain with the lock chain at
-	 * timer_delete_sync() by acquiring the lock_map around the fn()
-	 * call here and in timer_delete_sync().
+	 * del_timer_sync() by acquiring the lock_map around the fn()
+	 * call here and in del_timer_sync().
 	 */
 	lock_map_acquire(&lockdep_map);