4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner tglx@linutronix.de
commit d1f0301b3333eef5efbfa1fe0f0edbea01863d5d upstream.
The support of force threading interrupts which are set up with both a primary and a threaded handler wreckaged the setup of regular requested threaded interrupts (primary handler == NULL).
The reason is that it does not check whether the primary handler is set to the default handler which wakes the handler thread. Instead it replaces the thread handler with the primary handler as it would do with force threaded interrupts which have been requested via request_irq(). So both the primary and the thread handler become the same which then triggers the warnon that the thread handler tries to wakeup a not configured secondary thread.
Fortunately this only happens when the driver omits the IRQF_ONESHOT flag when requesting the threaded interrupt, which is normaly caught by the sanity checks when force irq threading is disabled.
Fix it by skipping the force threading setup when a regular threaded interrupt is requested. As a consequence the interrupt request which lacks the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging it.
Fixes: 2a1d3ab8986d ("genirq: Handle force threading of irqs with primary and thread handler") Reported-by: Kurt Kanzenbach kurt.kanzenbach@linutronix.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Kurt Kanzenbach kurt.kanzenbach@linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/irq/manage.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1026,6 +1026,13 @@ static int irq_setup_forced_threading(st if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) return 0;
+ /* + * No further action required for interrupts which are requested as + * threaded interrupts already + */ + if (new->handler == irq_default_primary_handler) + return 0; + new->flags |= IRQF_ONESHOT;
/* @@ -1033,7 +1040,7 @@ static int irq_setup_forced_threading(st * thread handler. We force thread them as well by creating a * secondary action. */ - if (new->handler != irq_default_primary_handler && new->thread_fn) { + if (new->handler && new->thread_fn) { /* Allocate the secondary action */ new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!new->secondary)