Revert "softirq: Let ksoftirqd do its job"

This reverts commit 4cd13c2.
It has been proven that this patch was not behaving corectly with our SoC
or Ethernet driver. We don't experience issues anymore when reverting it.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>

Author: noglitch

kernel/softirq.c

@@ -77,17 +77,6 @@ static void wakeup_softirqd(void)
 		wake_up_process(tsk);
 }
 
-/*
- * If ksoftirqd is scheduled, we do not want to process pending softirqs
- * right now. Let ksoftirqd handle this at its own rate, to get fairness.
- */
-static bool ksoftirqd_running(void)
-{
-	struct task_struct *tsk = __this_cpu_read(ksoftirqd);
-
-	return tsk && (tsk->state == TASK_RUNNING);
-}
-
 /*
  * preempt_count and SOFTIRQ_OFFSET usage:
  * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -324,7 +313,7 @@ asmlinkage __visible void do_softirq(void)
 
 	pending = local_softirq_pending();
 
-	if (pending && !ksoftirqd_running())
+	if (pending)
 		do_softirq_own_stack();
 
 	local_irq_restore(flags);
@@ -351,9 +340,6 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-	if (ksoftirqd_running())
-		return;
-
 	if (!force_irqthreads) {
 #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
 		/*