On 06/07/2015 17:35, Eric Auger wrote: >>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c >>> >> index 5d0f92b..efadbe5 100644 >>> >> --- a/kernel/irq/bypass.c >>> >> +++ b/kernel/irq/bypass.c >>> >> @@ -19,6 +19,42 @@ static LIST_HEAD(producers); >>> >> static LIST_HEAD(consumers); >>> >> static DEFINE_MUTEX(lock); >>> >> >>> >> +/* lock must be hold when calling connect */ >> > >> > If a lock must be held while callbacks are called, you have to document >> > that producers and consumers must _not_ call back into the IRQ bypass >> > manager. (If they have to, you have to document explicitly "This >> > function can be called from producer and consumer callbacks" whenever >> > relevant). > OK Thanks Also, please document on functions that take the irq bypass mutex that they can sleep. In fact irq_bypass_{,un}register_{producer,consumer} need kerneldoc comments. The good thing is that this helps a bit forming a lock hierarchy across the subsystems, for example irq bypass mutex outside vfio_platform_irq spinlock, because you cannot have a spinlock inside the mutex. I think that all of your six callbacks are fine. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html