From ee23871389d51e07380d23887333622fbe7d3dd9 Mon Sep 17 00:00:00 2001 From: Ivo Sieben Date: Mon, 3 Jun 2013 12:12:02 +0200 Subject: genirq: Set irq thread to RT priority on creation When a threaded irq handler is installed the irq thread is initially created on normal scheduling priority. Only after the irq thread is woken up it sets its priority to RT_FIFO MAX_USER_RT_PRIO/2 itself. This means that interrupts that occur directly after the irq handler is installed will be handled on a normal scheduling priority instead of the realtime priority that one would expect. Fix this by setting the RT priority on creation of the irq_thread. Signed-off-by: Ivo Sieben Cc: Sebastian Andrzej Siewior Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1370254322-17240-1-git-send-email-meltedpianoman@gmail.com Signed-off-by: Thomas Gleixner --- kernel/irq/manage.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'kernel/irq/manage.c') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index fa17855ca65..e16caa81f88 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -840,9 +840,6 @@ static void irq_thread_dtor(struct callback_head *unused) static int irq_thread(void *data) { struct callback_head on_exit_work; - static const struct sched_param param = { - .sched_priority = MAX_USER_RT_PRIO/2, - }; struct irqaction *action = data; struct irq_desc *desc = irq_to_desc(action->irq); irqreturn_t (*handler_fn)(struct irq_desc *desc, @@ -854,8 +851,6 @@ static int irq_thread(void *data) else handler_fn = irq_thread_fn; - sched_setscheduler(current, SCHED_FIFO, ¶m); - init_task_work(&on_exit_work, irq_thread_dtor); task_work_add(current, &on_exit_work, false); @@ -950,6 +945,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ if (new->thread_fn && !nested) { struct task_struct *t; + static const struct sched_param param = { + .sched_priority = MAX_USER_RT_PRIO/2, + }; t = kthread_create(irq_thread, new, "irq/%d-%s", irq, new->name); @@ -957,6 +955,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) ret = PTR_ERR(t); goto out_mput; } + + sched_setscheduler(t, SCHED_FIFO, ¶m); + /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code -- cgit v1.2.3-70-g09d2 From 2779db8d37d4b542d9ca2575f5f178dbeaca6c86 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 28 Jun 2013 02:40:30 +0100 Subject: genirq: Fix can_request_irq() for IRQs without an action Commit 02725e7471b8 ('genirq: Use irq_get/put functions'), inadvertently changed can_request_irq() to return 0 for IRQs that have no action. This causes pcibios_lookup_irq() to select only IRQs that already have an action with IRQF_SHARED set, or to fail if there are none. Change can_request_irq() to return 1 for IRQs that have no action (if the first two conditions are met). Reported-by: Bjarni Ingi Gislason Tested-by: Bjarni Ingi Gislason (against 3.2) Signed-off-by: Ben Hutchings Cc: 709647@bugs.debian.org Cc: stable@vger.kernel.org # 2.6.39+ Link: http://bugs.debian.org/709647 Link: http://lkml.kernel.org/r/1372383630.23847.40.camel@deadeye.wl.decadent.org.uk Signed-off-by: Thomas Gleixner --- kernel/irq/manage.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/irq/manage.c') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e16caa81f88..514bcfd855a 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -555,9 +555,9 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) return 0; if (irq_settings_can_request(desc)) { - if (desc->action) - if (irqflags & desc->action->flags & IRQF_SHARED) - canrequest =1; + if (!desc->action || + irqflags & desc->action->flags & IRQF_SHARED) + canrequest = 1; } irq_put_desc_unlock(desc, flags); return canrequest; -- cgit v1.2.3-70-g09d2