[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[Geert Uytterhoeven]

The sh73a0 INTC can't mask interrupts properly most likely due to a
hardware bug. Set the .control_parent flag to delegate masking to the
parent interrupt controller, like was already done for irqpin1.

Without this, accessing the three-axis digital accelerometer ADXL345
on kzm9g through /dev/input/event1 causes an interrupt storm, which
requires a power-cycle to recover from.

This was inspired by a patch for arch/arm/boot/dts/sh73a0.dtsi from
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: 341eb5465f67437a ("ARM: shmobile: INTC External IRQ pin driver on sh73a0")
---
 arch/arm/mach-shmobile/setup-sh73a0.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c b/arch/arm/mach-shmobile/setup-sh73a0.c
index 354cab111bf17ea6..613ce65184a6648c 100644
--- a/arch/arm/mach-shmobile/setup-sh73a0.c
+++ b/arch/arm/mach-shmobile/setup-sh73a0.c
@@ -595,6 +595,7 @@ static struct platform_device ipmmu_device = {
 
 static struct renesas_intc_irqpin_config irqpin0_platform_data = {
 	.irq_base = irq_pin(0), /* IRQ0 -> IRQ7 */
+	.control_parent = true,
 };
 
 static struct resource irqpin0_resources[] = {
@@ -656,6 +657,7 @@ static struct platform_device irqpin1_device = {
 
 static struct renesas_intc_irqpin_config irqpin2_platform_data = {
 	.irq_base = irq_pin(16), /* IRQ16 -> IRQ23 */
+	.control_parent = true,
 };
 
 static struct resource irqpin2_resources[] = {
@@ -686,6 +688,7 @@ static struct platform_device irqpin2_device = {
 
 static struct renesas_intc_irqpin_config irqpin3_platform_data = {
 	.irq_base = irq_pin(24), /* IRQ24 -> IRQ31 */
+	.control_parent = true,
 };
 
 static struct resource irqpin3_resources[] = {
-- 
1.9.1

[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[Laurent Pinchart]

Hi Geert,

Thank you for the patch.

On Tuesday 06 January 2015 14:39:10 Geert Uytterhoeven wrote:
> The sh73a0 INTC can't mask interrupts properly most likely due to a
> hardware bug. Set the .control_parent flag to delegate masking to the
> parent interrupt controller, like was already done for irqpin1.
> 
> Without this, accessing the three-axis digital accelerometer ADXL345
> on kzm9g through /dev/input/event1 causes an interrupt storm, which
> requires a power-cycle to recover from.
> 
> This was inspired by a patch for arch/arm/boot/dts/sh73a0.dtsi from
> Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>.

This looks correct to me, but shouldn't we concentrate on getting rid of 
legacy code instead ?

> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Fixes: 341eb5465f67437a ("ARM: shmobile: INTC External IRQ pin driver on
> sh73a0") ---
>  arch/arm/mach-shmobile/setup-sh73a0.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c
> b/arch/arm/mach-shmobile/setup-sh73a0.c index
> 354cab111bf17ea6..613ce65184a6648c 100644
> --- a/arch/arm/mach-shmobile/setup-sh73a0.c
> +++ b/arch/arm/mach-shmobile/setup-sh73a0.c
> @@ -595,6 +595,7 @@ static struct platform_device ipmmu_device = {
> 
>  static struct renesas_intc_irqpin_config irqpin0_platform_data = {
>  	.irq_base = irq_pin(0), /* IRQ0 -> IRQ7 */
> +	.control_parent = true,
>  };
> 
>  static struct resource irqpin0_resources[] = {
> @@ -656,6 +657,7 @@ static struct platform_device irqpin1_device = {
> 
>  static struct renesas_intc_irqpin_config irqpin2_platform_data = {
>  	.irq_base = irq_pin(16), /* IRQ16 -> IRQ23 */
> +	.control_parent = true,
>  };
> 
>  static struct resource irqpin2_resources[] = {
> @@ -686,6 +688,7 @@ static struct platform_device irqpin2_device = {
> 
>  static struct renesas_intc_irqpin_config irqpin3_platform_data = {
>  	.irq_base = irq_pin(24), /* IRQ24 -> IRQ31 */
> +	.control_parent = true,
>  };
> 
>  static struct resource irqpin3_resources[] = {

-- 
Regards,

Laurent Pinchart

[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[Simon Horman]

On Tue, Jan 06, 2015 at 04:14:09PM +0200, Laurent Pinchart wrote:
> Hi Geert,
> 
> Thank you for the patch.
> 
> On Tuesday 06 January 2015 14:39:10 Geert Uytterhoeven wrote:
> > The sh73a0 INTC can't mask interrupts properly most likely due to a
> > hardware bug. Set the .control_parent flag to delegate masking to the
> > parent interrupt controller, like was already done for irqpin1.
> > 
> > Without this, accessing the three-axis digital accelerometer ADXL345
> > on kzm9g through /dev/input/event1 causes an interrupt storm, which
> > requires a power-cycle to recover from.
> > 
> > This was inspired by a patch for arch/arm/boot/dts/sh73a0.dtsi from
> > Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>.
> 
> This looks correct to me, but shouldn't we concentrate on getting rid of 
> legacy code instead ?

Probably, but as we now have this patch I'm inclined to apply it.

> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Fixes: 341eb5465f67437a ("ARM: shmobile: INTC External IRQ pin driver on
> > sh73a0") ---
> >  arch/arm/mach-shmobile/setup-sh73a0.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c
> > b/arch/arm/mach-shmobile/setup-sh73a0.c index
> > 354cab111bf17ea6..613ce65184a6648c 100644
> > --- a/arch/arm/mach-shmobile/setup-sh73a0.c
> > +++ b/arch/arm/mach-shmobile/setup-sh73a0.c
> > @@ -595,6 +595,7 @@ static struct platform_device ipmmu_device = {
> > 
> >  static struct renesas_intc_irqpin_config irqpin0_platform_data = {
> >  	.irq_base = irq_pin(0), /* IRQ0 -> IRQ7 */
> > +	.control_parent = true,
> >  };
> > 
> >  static struct resource irqpin0_resources[] = {
> > @@ -656,6 +657,7 @@ static struct platform_device irqpin1_device = {
> > 
> >  static struct renesas_intc_irqpin_config irqpin2_platform_data = {
> >  	.irq_base = irq_pin(16), /* IRQ16 -> IRQ23 */
> > +	.control_parent = true,
> >  };
> > 
> >  static struct resource irqpin2_resources[] = {
> > @@ -686,6 +688,7 @@ static struct platform_device irqpin2_device = {
> > 
> >  static struct renesas_intc_irqpin_config irqpin3_platform_data = {
> >  	.irq_base = irq_pin(24), /* IRQ24 -> IRQ31 */
> > +	.control_parent = true,
> >  };
> > 
> >  static struct resource irqpin3_resources[] = {
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[Geert Uytterhoeven]

Hi Laurent,

On Tue, Jan 6, 2015 at 3:14 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Tuesday 06 January 2015 14:39:10 Geert Uytterhoeven wrote:
>> The sh73a0 INTC can't mask interrupts properly most likely due to a
>> hardware bug. Set the .control_parent flag to delegate masking to the
>> parent interrupt controller, like was already done for irqpin1.
>>
>> Without this, accessing the three-axis digital accelerometer ADXL345
>> on kzm9g through /dev/input/event1 causes an interrupt storm, which
>> requires a power-cycle to recover from.
>>
>> This was inspired by a patch for arch/arm/boot/dts/sh73a0.dtsi from
>> Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>.
>
> This looks correct to me, but shouldn't we concentrate on getting rid of
> legacy code instead ?

Sure.

But this is a serious bug, which allows to crash the kernel from user space.
Worse, a simple reset is not sufficient to recover. You need to power-cycle
the board.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances

[Simon Horman]

On Wed, Jan 07, 2015 at 09:14:19AM +0100, Geert Uytterhoeven wrote:
> Hi Laurent,
> 
> On Tue, Jan 6, 2015 at 3:14 PM, Laurent Pinchart
> <laurent.pinchart@ideasonboard.com> wrote:
> > On Tuesday 06 January 2015 14:39:10 Geert Uytterhoeven wrote:
> >> The sh73a0 INTC can't mask interrupts properly most likely due to a
> >> hardware bug. Set the .control_parent flag to delegate masking to the
> >> parent interrupt controller, like was already done for irqpin1.
> >>
> >> Without this, accessing the three-axis digital accelerometer ADXL345
> >> on kzm9g through /dev/input/event1 causes an interrupt storm, which
> >> requires a power-cycle to recover from.
> >>
> >> This was inspired by a patch for arch/arm/boot/dts/sh73a0.dtsi from
> >> Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>.
> >
> > This looks correct to me, but shouldn't we concentrate on getting rid of
> > legacy code instead ?
> 
> Sure.
> 
> But this is a serious bug, which allows to crash the kernel from user space.
> Worse, a simple reset is not sufficient to recover. You need to power-cycle
> the board.

With that in mind I have queued this up as a fix for v3.19.

For (my) reference, 341eb5465f67437a ("ARM: shmobile: INTC External IRQ pin
driver on sh73a0"), which this patch fixes, was part of v3.9.