From be09ef09e290e1c8bd361e431d3659e13e65094c Mon Sep 17 00:00:00 2001 From: Jiaxun Yang Date: Wed, 25 Mar 2020 11:54:55 +0800 Subject: [PATCH] irqchip: loongson-liointc: Workaround LPC IRQ Errata The 1.0 version of that controller has a bug that status bit of LPC IRQ sometimes doesn't get set correctly. So we can always blame LPC IRQ when spurious interrupt happens at the parent interrupt line which LPC IRQ supposed to route to. Signed-off-by: Jiaxun Yang Co-developed-by: Huacai Chen Signed-off-by: Huacai Chen Reviewed-by: Marc Zyngier Signed-off-by: Thomas Bogendoerfer --- drivers/irqchip/irq-loongson-liointc.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c index 18de2c0..63b6147 100644 --- a/drivers/irqchip/irq-loongson-liointc.c +++ b/drivers/irqchip/irq-loongson-liointc.c @@ -32,6 +32,8 @@ #define LIOINTC_SHIFT_INTx 4 +#define LIOINTC_ERRATA_IRQ 10 + struct liointc_handler_data { struct liointc_priv *priv; u32 parent_int_map; @@ -41,6 +43,7 @@ struct liointc_priv { struct irq_chip_generic *gc; struct liointc_handler_data handler[LIOINTC_NUM_PARENT]; u8 map_cache[LIOINTC_CHIP_IRQ]; + bool has_lpc_irq_errata; }; static void liointc_chained_handle_irq(struct irq_desc *desc) @@ -54,8 +57,15 @@ static void liointc_chained_handle_irq(struct irq_desc *desc) pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS); - if (!pending) - spurious_interrupt(); + if (!pending) { + /* Always blame LPC IRQ if we have that bug */ + if (handler->priv->has_lpc_irq_errata && + (handler->parent_int_map & ~gc->mask_cache & + BIT(LIOINTC_ERRATA_IRQ))) + pending = BIT(LIOINTC_ERRATA_IRQ); + else + spurious_interrupt(); + } while (pending) { int bit = __ffs(pending); -- 2.7.4