irqchip/realtek-rtl: Service all pending interrupts

[ Upstream commit 960dd88 ]

Instead of only servicing the lowest pending interrupt line, make sure
all pending SoC interrupts are serviced before exiting the chained
handler. This adds a small overhead if only one interrupt is pending,
but should prevent rapid re-triggering of the handler.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/5082ad3cb8b4eedf55075561b93eff6570299fe1.1641739718.git.sander@svanheule.net
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/irqchip/irq-realtek-rtl.c

@@ -76,16 +76,20 @@ static void realtek_irq_dispatch(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct irq_domain *domain;
-	unsigned int pending;
+	unsigned long pending;
+	unsigned int soc_int;
 
 	chained_irq_enter(chip, desc);
 	pending = readl(REG(RTL_ICTL_GIMR)) & readl(REG(RTL_ICTL_GISR));
+
 	if (unlikely(!pending)) {
 		spurious_interrupt();
 		goto out;
 	}
+
 	domain = irq_desc_get_handler_data(desc);
-	generic_handle_domain_irq(domain, __ffs(pending));
+	for_each_set_bit(soc_int, &pending, 32)
+		generic_handle_domain_irq(domain, soc_int);
 
 out:
 	chained_irq_exit(chip, desc);