According to the datasheet[1], the Interrupt IRQ Pending Registers are read-only. The implementation of sun4i_irq_ack() is wrong because it writes to these read-only registers.
This patch removes the wrong irq_ack callback implementation and all the code writing to these read-only registers in sun4i_of_init(). [1] http://dl.linux-sunxi.org/A10/A10%20User%20Manual%20-%20v1.20%20%282012-04-09%2c%20DECRYPTED%29.pdf Signed-off-by: Axel Lin <axel....@ingics.com> Acked-by: Maxime Ripard <maxime.rip...@free-electrons.com> --- Hi Thomas, This patch was sent on https://lkml.org/lkml/2013/7/6/59 with Maxime's Ack. And re-sent on https://lkml.org/lkml/2013/7/19/229 I change the subject line as the patch does is to avoid writing to read-only registers. Axel drivers/irqchip/irq-sun4i.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c index a5438d8..29b75c0a 100644 --- a/drivers/irqchip/irq-sun4i.c +++ b/drivers/irqchip/irq-sun4i.c @@ -38,18 +38,6 @@ static struct irq_domain *sun4i_irq_domain; static asmlinkage void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs); -static void sun4i_irq_ack(struct irq_data *irqd) -{ - unsigned int irq = irqd_to_hwirq(irqd); - unsigned int irq_off = irq % 32; - int reg = irq / 32; - u32 val; - - val = readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg)); - writel(val | (1 << irq_off), - sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg)); -} - static void sun4i_irq_mask(struct irq_data *irqd) { unsigned int irq = irqd_to_hwirq(irqd); @@ -76,7 +64,6 @@ static void sun4i_irq_unmask(struct irq_data *irqd) static struct irq_chip sun4i_irq_chip = { .name = "sun4i_irq", - .irq_ack = sun4i_irq_ack, .irq_mask = sun4i_irq_mask, .irq_unmask = sun4i_irq_unmask, }; @@ -114,11 +101,6 @@ static int __init sun4i_of_init(struct device_node *node, writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1)); writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2)); - /* Clear all the pending interrupts */ - writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)); - writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1)); - writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2)); - /* Enable protection mode */ writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG); -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
