From 9ece8839b1277fb9128ff6833411614ab6c88d68 Mon Sep 17 00:00:00 2001 From: Evgeniy Dushistov Date: Sat, 26 Jul 2014 19:56:59 +0400 Subject: [PATCH] ARM: orion: Fix for certain sequence of request_irq can cause irq storm The problem is that hardware handled by arm/plat-orion/gpio.c, require ack for edge irq, and no ack for level irq. The code handle this issue, by two "struct irq_chip_type" per one "struct irq_chip_generic". For one "struct irq_chip_generic" irq_ack pointer is setted, for another it is NULL. But we have only one mask_cache per two "struct irq_chip_type". So if we 1)unmask interrupt A for "edge type" trigger, 2)unmask interrupt B for "level type" trigger, 3)unmask interrupt C for "edge type", we, because of usage of generic irq_gc_mask_clr_bit/irq_gc_mask_set_bit, have hardware configured to trigger interrupt B on "edge type", because of shared mask_cache. But kernel think that B is "level type", so when interrupt B occur via "edge" reason, we don't ack it, and B triggered again and again. Signed-off-by: Evgeniy A. Dushistov Link: https://lkml.kernel.org/r/20140726155659.GA22977@fifteen Signed-off-by: Jason Cooper --- arch/arm/plat-orion/gpio.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c index b61a3bcc2fa8..e048f6198d68 100644 --- a/arch/arm/plat-orion/gpio.c +++ b/arch/arm/plat-orion/gpio.c @@ -497,6 +497,34 @@ static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) #define orion_gpio_dbg_show NULL #endif +static void orion_gpio_unmask_irq(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + struct irq_chip_type *ct = irq_data_get_chip_type(d); + u32 reg_val; + u32 mask = d->mask; + + irq_gc_lock(gc); + reg_val = irq_reg_readl(gc->reg_base + ct->regs.mask); + reg_val |= mask; + irq_reg_writel(reg_val, gc->reg_base + ct->regs.mask); + irq_gc_unlock(gc); +} + +static void orion_gpio_mask_irq(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + struct irq_chip_type *ct = irq_data_get_chip_type(d); + u32 mask = d->mask; + u32 reg_val; + + irq_gc_lock(gc); + reg_val = irq_reg_readl(gc->reg_base + ct->regs.mask); + reg_val &= ~mask; + irq_reg_writel(reg_val, gc->reg_base + ct->regs.mask); + irq_gc_unlock(gc); +} + void __init orion_gpio_init(struct device_node *np, int gpio_base, int ngpio, void __iomem *base, int mask_offset, @@ -565,8 +593,8 @@ void __init orion_gpio_init(struct device_node *np, ct = gc->chip_types; ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF; ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW; - ct->chip.irq_mask = irq_gc_mask_clr_bit; - ct->chip.irq_unmask = irq_gc_mask_set_bit; + ct->chip.irq_mask = orion_gpio_mask_irq; + ct->chip.irq_unmask = orion_gpio_unmask_irq; ct->chip.irq_set_type = gpio_irq_set_type; ct->chip.name = ochip->chip.label; @@ -575,8 +603,8 @@ void __init orion_gpio_init(struct device_node *np, ct->regs.ack = GPIO_EDGE_CAUSE_OFF; ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING; ct->chip.irq_ack = irq_gc_ack_clr_bit; - ct->chip.irq_mask = irq_gc_mask_clr_bit; - ct->chip.irq_unmask = irq_gc_mask_set_bit; + ct->chip.irq_mask = orion_gpio_mask_irq; + ct->chip.irq_unmask = orion_gpio_unmask_irq; ct->chip.irq_set_type = gpio_irq_set_type; ct->handler = handle_edge_irq; ct->chip.name = ochip->chip.label; -- GitLab