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

From: Greg Kroah-Hartman
Date: Wed Jul 17 2019 - 23:08:51 EST


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)
{