PM / freezer: Abort suspend when there's a wakeup while freezing

Although try_to_freeze_tasks() stops when there's a wakeup, it doesn't
return an error when it successfully freezes everything it wants to freeze.
As a result, the suspend attempt can continue even after a wakeup is
issued. Although the wakeup will be eventually caught later in the suspend
process, kicking the can down the road is suboptimal; when there's a wakeup
detected, suspend should be immediately aborted by returning an error
instead. Make try_to_freeze_tasks() do just that, and also move the wakeup
check above the `todo` check so that we don't miss a wakeup from a process
that successfully froze.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Change-Id: I6d0ff54b1e1e143df2679d3848019590725c6351

kernel/power/process.c

@@ -65,14 +65,14 @@ static int try_to_freeze_tasks(bool user_only)
 			todo += wq_busy;
 		}
 
-		if (!todo || time_after(jiffies, end_time))
-			break;
-
 		if (pm_wakeup_pending()) {
 			wakeup = true;
 			break;
 		}
 
+		if (!todo || time_after(jiffies, end_time))
+			break;
+
 		/*
 		 * We need to retry, but first give the freezing tasks some
 		 * time to enter the refrigerator.  Start with an initial
@@ -113,7 +113,7 @@ static int try_to_freeze_tasks(bool user_only)
 			elapsed_msecs % 1000);
 	}
 
-	return todo ? -EBUSY : 0;
+	return todo || wakeup ? -EBUSY : 0;
 }
 
 /**