[PATCH RESEND] irqchip: sun4i: Don't write to read-only registers
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
Acked-by: Maxime Ripard
---
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(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
- writel(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
- writel(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
-
/* Enable protection mode */
writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
--
1.8.1.2
--
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[PATCH RESEND] irqchip: sun4i: Don't write to read-only registers
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(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
- writel(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
- writel(0x, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
-
/* Enable protection mode */
writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
--
1.8.1.2
--
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Please read the FAQ at http://www.tux.org/lkml/
