Two threads can try to fire the irq_sim with different offsets and will end up fighting for the irq_work asignment. To fix it: add a mutex and lock it before firing.
Suggested-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de> Signed-off-by: Bartosz Golaszewski <b...@bgdev.pl> --- include/linux/irq_sim.h | 1 + kernel/irq/irq_sim.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h index 630a57e55db6..676bfa0c12b9 100644 --- a/include/linux/irq_sim.h +++ b/include/linux/irq_sim.h @@ -29,6 +29,7 @@ struct irq_sim { int irq_base; unsigned int irq_count; struct irq_sim_irq_ctx *irqs; + struct mutex lock; }; int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs); diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c index dd20d0d528d4..2f06c24b51a0 100644 --- a/kernel/irq/irq_sim.c +++ b/kernel/irq/irq_sim.c @@ -74,6 +74,7 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) } init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq); + mutex_init(&sim->lock); sim->irq_count = num_irqs; return sim->irq_base; @@ -142,10 +143,14 @@ EXPORT_SYMBOL_GPL(devm_irq_sim_init); */ void irq_sim_fire(struct irq_sim *sim, unsigned int offset) { + mutex_lock(&sim->lock); + if (sim->irqs[offset].enabled) { sim->work_ctx.irq = irq_sim_irqnum(sim, offset); irq_work_queue(&sim->work_ctx.work); } + + mutex_unlock(&sim->lock); } EXPORT_SYMBOL_GPL(irq_sim_fire); -- 2.19.1