[tip:x86/apic] genirq: Fix misleading synchronize_irq() documentation

[tip-bot for Thomas Gleixner <tipbot@zytor.com>]

Commit-ID:  1d21f2af8571c6a6a44e7c1911780614847b0253
Gitweb:     https://git.kernel.org/tip/1d21f2af8571c6a6a44e7c1911780614847b0253
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri, 28 Jun 2019 13:11:50 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 3 Jul 2019 10:12:29 +0200

genirq: Fix misleading synchronize_irq() documentation

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.189241552@linutronix.de

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

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index dc8b35f2d545..44fc505815d6 100644
--- 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)
 {