diff --git a/drivers/misc/rp1/rp1_pci.c b/drivers/misc/rp1/rp1_pci.c
index d210da84c30a..81685e3f3296 100644
--- a/drivers/misc/rp1/rp1_pci.c
+++ b/drivers/misc/rp1/rp1_pci.c
@@ -143,6 +143,7 @@ static int rp1_irq_activate(struct irq_domain *d, struct irq_data *irqd,
 	struct rp1_dev *rp1 = d->host_data;
 
 	msix_cfg_set(rp1, (unsigned int)irqd->hwirq, MSIX_CFG_ENABLE);
+	msix_cfg_set(rp1, (unsigned int)irqd->hwirq, MSIX_CFG_IACK);
 
 	return 0;
 }