[PATCH 4.19 31/47] genirq: Fix misleading synchronize_irq() documentation

[Greg Kroah-Hartman]

From: Thomas Gleixner tglx@xxxxxxxxxxxxx

commit 1d21f2af8571c6a6a44e7c1911780614847b0253 upstream

The function might sleep, so it cannot be called from interrupt
context. Not even with care.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Link: https://lkml.kernel.org/r/20190628111440.189241552@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


---
 kernel/irq/manage.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -96,7 +96,8 @@ EXPORT_SYMBOL(synchronize_hardirq);
  *	to complete before returning. If you use this function while
  *	holding a resource the IRQ handler may need you will deadlock.
  *
- *	This function may be called - with care - from IRQ context.
+ *	Can only be called from preemptible code as it might sleep when
+ *	an interrupt thread is associated to @irq.
  */
 void synchronize_irq(unsigned int irq)
 {