genirq: Remove paranoid warnons and bogus fixups
Alexander pointed out that the warnons in the regular exit path are
bogus and the thread_mask one actually could be triggered when
__setup_irq() hands out that thread_mask again after __free_irq()
dropped irq_desc->lock.
Thinking more about it, neither IRQTF_RUNTHREAD nor the bit in
thread_mask can be set as this is the regular exit path. We come here
due to:
__free_irq()
remove action from desc
synchronize_irq()
kthread_stop()
So synchronize_irq() makes sure that the thread finished running and
cleaned up both the thread_active count and thread_mask. After that
point nothing can set IRQTF_RUNTHREAD on this action. So the warnons
and the cleanups are pointless.
Reported-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Ido Yariv <ido@wizery.com>
Link: http://lkml.kernel.org/r/20120315190755.GA6732@dhcp-26-207.brq.redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 453feed..b0ccd1a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -804,17 +804,11 @@
* This is the regular exit path. __free_irq() is stopping the
* thread via kthread_stop() after calling
* synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
- * oneshot mask bit should be set.
+ * oneshot mask bit can be set. We cannot verify that as we
+ * cannot touch the oneshot mask at this point anymore as
+ * __setup_irq() might have given out currents thread_mask
+ * again.
*
- * Verify that this is true.
- */
- if (WARN_ON(test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)))
- wake_threads_waitq(desc);
-
- if (WARN_ON(desc->threads_oneshot & action->thread_mask))
- irq_finalize_oneshot(desc, action, true);
-
- /*
* Clear irq_thread. Otherwise exit_irq_thread() would make
* fuzz about an active irq thread going into nirvana.
*/
