Patchwork [7/8] powerpc/5200: Refactor mpc5200 interrupt controller driver

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Submitter Grant Likely
Date Jan. 21, 2009, 8:55 p.m.
Message ID <20090121205540.31232.77034.stgit@localhost.localdomain>
Download mbox | patch
Permalink /patch/19699/
State Superseded, archived
Delegated to: Grant Likely
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Comments

Grant Likely - Jan. 21, 2009, 8:55 p.m.
From: Grant Likely <grant.likely@secretlab.ca>

Rework the mpc5200-pic driver to simplify it and fix up the setting
of desc->status when set_type is called for internal IRQs (so they
are reported as level, not edge).  The simplification is due to
splitting off the handling of external IRQs into a separate block
so they don't need to be handled as exceptions in the normal
CRIT, MAIN and PERP paths.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Wolfram Sang <w.sang@pengutronix.de>
---

 arch/powerpc/platforms/52xx/mpc52xx_pic.c |  145 ++++++++++++-----------------
 1 files changed, 58 insertions(+), 87 deletions(-)
Wolfgang Grandegger - Jan. 25, 2009, 8:06 p.m.
Grant Likely wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
> 
> Rework the mpc5200-pic driver to simplify it and fix up the setting
> of desc->status when set_type is called for internal IRQs (so they
> are reported as level, not edge).  The simplification is due to
> splitting off the handling of external IRQs into a separate block
> so they don't need to be handled as exceptions in the normal
> CRIT, MAIN and PERP paths.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: Wolfram Sang <w.sang@pengutronix.de>
> ---
> 
>  arch/powerpc/platforms/52xx/mpc52xx_pic.c |  145 ++++++++++++-----------------
>  1 files changed, 58 insertions(+), 87 deletions(-)
> 
> 
> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> index c0a9559..277c9c5 100644
> --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> @@ -190,10 +190,10 @@ static void mpc52xx_extirq_ack(unsigned int virq)
>  
>  static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>  {
> -	struct irq_desc *desc = get_irq_desc(virq);
>  	u32 ctrl_reg, type;
>  	int irq;
>  	int l2irq;
> +	void *handler = handle_level_irq;
>  
>  	irq = irq_map[virq].hwirq;
>  	l2irq = irq & MPC52xx_IRQ_L2_MASK;
> @@ -201,32 +201,21 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>  	pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
>  
>  	switch (flow_type) {
> -	case IRQF_TRIGGER_HIGH:
> -		type = 0;
> -		break;
> -	case IRQF_TRIGGER_RISING:
> -		type = 1;
> -		break;
> -	case IRQF_TRIGGER_FALLING:
> -		type = 2;
> -		break;
> -	case IRQF_TRIGGER_LOW:
> -		type = 3;
> -		break;
> +	case IRQF_TRIGGER_HIGH: type = 0; break;
> +	case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
> +	case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
> +	case IRQF_TRIGGER_LOW: type = 3; break;

The Linux coding style tells us not to do that:

http://lxr.linux.no/linux+v2.6.28.2/Documentation/CodingStyle#L60

Wolfgang.
Grant Likely - Jan. 26, 2009, 12:22 a.m.
On Sun, Jan 25, 2009 at 1:06 PM, Wolfgang Grandegger <wg@grandegger.com> wrote:
> Grant Likely wrote:
>> From: Grant Likely <grant.likely@secretlab.ca>
>>
>> Rework the mpc5200-pic driver to simplify it and fix up the setting
>> of desc->status when set_type is called for internal IRQs (so they
>> are reported as level, not edge).  The simplification is due to
>> splitting off the handling of external IRQs into a separate block
>> so they don't need to be handled as exceptions in the normal
>> CRIT, MAIN and PERP paths.
>>
>> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
>> CC: Wolfram Sang <w.sang@pengutronix.de>
>> ---
>>
>>  arch/powerpc/platforms/52xx/mpc52xx_pic.c |  145 ++++++++++++-----------------
>>  1 files changed, 58 insertions(+), 87 deletions(-)
>>
>>
>> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>> index c0a9559..277c9c5 100644
>> --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>> +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>> @@ -190,10 +190,10 @@ static void mpc52xx_extirq_ack(unsigned int virq)
>>
>>  static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>>  {
>> -     struct irq_desc *desc = get_irq_desc(virq);
>>       u32 ctrl_reg, type;
>>       int irq;
>>       int l2irq;
>> +     void *handler = handle_level_irq;
>>
>>       irq = irq_map[virq].hwirq;
>>       l2irq = irq & MPC52xx_IRQ_L2_MASK;
>> @@ -201,32 +201,21 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>>       pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
>>
>>       switch (flow_type) {
>> -     case IRQF_TRIGGER_HIGH:
>> -             type = 0;
>> -             break;
>> -     case IRQF_TRIGGER_RISING:
>> -             type = 1;
>> -             break;
>> -     case IRQF_TRIGGER_FALLING:
>> -             type = 2;
>> -             break;
>> -     case IRQF_TRIGGER_LOW:
>> -             type = 3;
>> -             break;
>> +     case IRQF_TRIGGER_HIGH: type = 0; break;
>> +     case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
>> +     case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
>> +     case IRQF_TRIGGER_LOW: type = 3; break;
>
> The Linux coding style tells us not to do that:
>
> http://lxr.linux.no/linux+v2.6.28.2/Documentation/CodingStyle#L60

In principle I agree and follow that rule most of the time, but I have
good reason for not choosing to do so here.

The whole point of coding style is to promote
readability/manageability.  ie. the 80 column rule is a very strong
guideline, but there are places where breaking that rule makes for
more readable code than breaking things up and it is left to the
discretion of the coder and the maintainer.

In this case I looked at the block of code and saw that a large number
of lines (11) were needed to do a set of nearly identical operations.
I chose to line them up because in my opinion it is easier to follow
the pattern with them written in horizontal columns instead of in
vertical blocks.  In other words, in this case it is harder to hide
something in the code written this way because it wouldn't match the
pattern of the other lines.  For the same reason you'll also notice
that I did *not* put all the statements on the same line for the
default case because it doesn't match the pattern of the specific
cases.

g.
Wolfgang Denk - Jan. 26, 2009, 6:26 a.m.
Dear Grant Likely,

In message <fa686aa40901251622j542b6029u83c510f5b4e2f92@mail.gmail.com> you wrote:
>
> >> -     case IRQF_TRIGGER_HIGH:
> >> -             type = 0;
> >> -             break;
> >> -     case IRQF_TRIGGER_RISING:
> >> -             type = 1;
> >> -             break;
> >> -     case IRQF_TRIGGER_FALLING:
> >> -             type = 2;
> >> -             break;
> >> -     case IRQF_TRIGGER_LOW:
> >> -             type = 3;
> >> -             break;
> >> +     case IRQF_TRIGGER_HIGH: type = 0; break;
> >> +     case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
> >> +     case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
> >> +     case IRQF_TRIGGER_LOW: type = 3; break;
> >
> > The Linux coding style tells us not to do that:
...
> In principle I agree and follow that rule most of the time, but I have
> good reason for not choosing to do so here.
> 
> The whole point of coding style is to promote
> readability/manageability.  ie. the 80 column rule is a very strong
> guideline, but there are places where breaking that rule makes for
> more readable code than breaking things up and it is left to the
> discretion of the coder and the maintainer.

It's not so much the line length, IMO.

It's "Don't put multiple statements on a single line", plus
readability.

I think the new version is more difficult to read. It's plain ugly,
and inconsistent.

Best regards,

Wolfgang Denk
Wolfgang Grandegger - Jan. 26, 2009, 8:31 a.m.
Grant Likely wrote:
> On Sun, Jan 25, 2009 at 1:06 PM, Wolfgang Grandegger <wg@grandegger.com> wrote:
>> Grant Likely wrote:
>>> From: Grant Likely <grant.likely@secretlab.ca>
>>>
>>> Rework the mpc5200-pic driver to simplify it and fix up the setting
>>> of desc->status when set_type is called for internal IRQs (so they
>>> are reported as level, not edge).  The simplification is due to
>>> splitting off the handling of external IRQs into a separate block
>>> so they don't need to be handled as exceptions in the normal
>>> CRIT, MAIN and PERP paths.
>>>
>>> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
>>> CC: Wolfram Sang <w.sang@pengutronix.de>
>>> ---
>>>
>>>  arch/powerpc/platforms/52xx/mpc52xx_pic.c |  145 ++++++++++++-----------------
>>>  1 files changed, 58 insertions(+), 87 deletions(-)
>>>
>>>
>>> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>>> index c0a9559..277c9c5 100644
>>> --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>>> +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
>>> @@ -190,10 +190,10 @@ static void mpc52xx_extirq_ack(unsigned int virq)
>>>
>>>  static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>>>  {
>>> -     struct irq_desc *desc = get_irq_desc(virq);
>>>       u32 ctrl_reg, type;
>>>       int irq;
>>>       int l2irq;
>>> +     void *handler = handle_level_irq;
>>>
>>>       irq = irq_map[virq].hwirq;
>>>       l2irq = irq & MPC52xx_IRQ_L2_MASK;
>>> @@ -201,32 +201,21 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>>>       pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
>>>
>>>       switch (flow_type) {
>>> -     case IRQF_TRIGGER_HIGH:
>>> -             type = 0;
>>> -             break;
>>> -     case IRQF_TRIGGER_RISING:
>>> -             type = 1;
>>> -             break;
>>> -     case IRQF_TRIGGER_FALLING:
>>> -             type = 2;
>>> -             break;
>>> -     case IRQF_TRIGGER_LOW:
>>> -             type = 3;
>>> -             break;
>>> +     case IRQF_TRIGGER_HIGH: type = 0; break;
>>> +     case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
>>> +     case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
>>> +     case IRQF_TRIGGER_LOW: type = 3; break;
>> The Linux coding style tells us not to do that:
>>
>> http://lxr.linux.no/linux+v2.6.28.2/Documentation/CodingStyle#L60
> 
> In principle I agree and follow that rule most of the time, but I have
> good reason for not choosing to do so here.
> 
> The whole point of coding style is to promote
> readability/manageability.  ie. the 80 column rule is a very strong
> guideline, but there are places where breaking that rule makes for
> more readable code than breaking things up and it is left to the
> discretion of the coder and the maintainer.
> 
> In this case I looked at the block of code and saw that a large number
> of lines (11) were needed to do a set of nearly identical operations.
> I chose to line them up because in my opinion it is easier to follow
> the pattern with them written in horizontal columns instead of in
> vertical blocks.  In other words, in this case it is harder to hide
> something in the code written this way because it wouldn't match the
> pattern of the other lines.  For the same reason you'll also notice
> that I did *not* put all the statements on the same line for the
> default case because it doesn't match the pattern of the specific
> cases.

Well, I don't want to debate coding style rules. I also sometimes just
shake my head. But this rules I actually find useful because it allows
the GDB to point to the line == expression, apart from readability. If
you don't stick to the coding style rules, you have to explain to the
maintainer why you broke it ... good luck ;-).

Wolfgang.
Wolfram Sang - Jan. 26, 2009, 9:22 a.m.
Hi Grant,

> I chose to line them up because in my opinion it is easier to follow
> the pattern with them written in horizontal columns instead of in
> vertical blocks.

I also think the original coding style is easier to read.

Kind regards,

   Wolfram
Matt Sealey - Jan. 26, 2009, 5:58 p.m.
> Well, I don't want to debate coding style rules. I also sometimes just
> shake my head. But this rules I actually find useful because it allows
> the GDB to point to the line == expression, apart from readability. If
> you don't stick to the coding style rules, you have to explain to the
> maintainer why you broke it ... good luck ;-).

I thought Grant *WAS* the MPC52xx maintainer :D
Matt Sealey - Jan. 27, 2009, 5:52 p.m.
On Wed, Jan 21, 2009 at 2:55 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
>
> Rework the mpc5200-pic driver to simplify it and fix up the setting
> of desc->status when set_type is called for internal IRQs (so they
> are reported as level, not edge).  The simplification is due to
> splitting off the handling of external IRQs into a separate block
> so they don't need to be handled as exceptions in the normal
> CRIT, MAIN and PERP paths.
>
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: Wolfram Sang <w.sang@pengutronix.de>

Can I assume this has absolutely no functional impact compared to the
old one? It doesn't change any behaviour, just implements exactly the
same in a much nicer way?
Grant Likely - Jan. 27, 2009, 5:54 p.m.
On Tue, Jan 27, 2009 at 10:52 AM, Matt Sealey <matt@genesi-usa.com> wrote:
> On Wed, Jan 21, 2009 at 2:55 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
>> From: Grant Likely <grant.likely@secretlab.ca>
>>
>> Rework the mpc5200-pic driver to simplify it and fix up the setting
>> of desc->status when set_type is called for internal IRQs (so they
>> are reported as level, not edge).  The simplification is due to
>> splitting off the handling of external IRQs into a separate block
>> so they don't need to be handled as exceptions in the normal
>> CRIT, MAIN and PERP paths.
>
> Can I assume this has absolutely no functional impact compared to the
> old one? It doesn't change any behaviour, just implements exactly the
> same in a much nicer way?

Plus small bug fixes.  It should have no functional impact on stuff
that already works.

g.
Wolfram Sang - Jan. 29, 2009, 9:33 p.m.
On Wed, Jan 21, 2009 at 01:55:41PM -0700, Grant Likely wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
> 
> Rework the mpc5200-pic driver to simplify it and fix up the setting
> of desc->status when set_type is called for internal IRQs (so they
> are reported as level, not edge).  The simplification is due to
> splitting off the handling of external IRQs into a separate block
> so they don't need to be handled as exceptions in the normal
> CRIT, MAIN and PERP paths.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: Wolfram Sang <w.sang@pengutronix.de>

Can't say much about this one as I have never dealt with the PIC
directly so far. Yet, my phyCORE-MPC5200B-tiny behaves normal, so

Tested-by: Wolfram Sang <w.sang@pengutronix.de>

> ---
> 
>  arch/powerpc/platforms/52xx/mpc52xx_pic.c |  145 ++++++++++++-----------------
>  1 files changed, 58 insertions(+), 87 deletions(-)
> 
> 
> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> index c0a9559..277c9c5 100644
> --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
> @@ -190,10 +190,10 @@ static void mpc52xx_extirq_ack(unsigned int virq)
>  
>  static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>  {
> -	struct irq_desc *desc = get_irq_desc(virq);
>  	u32 ctrl_reg, type;
>  	int irq;
>  	int l2irq;
> +	void *handler = handle_level_irq;
>  
>  	irq = irq_map[virq].hwirq;
>  	l2irq = irq & MPC52xx_IRQ_L2_MASK;
> @@ -201,32 +201,21 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
>  	pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
>  
>  	switch (flow_type) {
> -	case IRQF_TRIGGER_HIGH:
> -		type = 0;
> -		break;
> -	case IRQF_TRIGGER_RISING:
> -		type = 1;
> -		break;
> -	case IRQF_TRIGGER_FALLING:
> -		type = 2;
> -		break;
> -	case IRQF_TRIGGER_LOW:
> -		type = 3;
> -		break;
> +	case IRQF_TRIGGER_HIGH: type = 0; break;
> +	case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
> +	case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
> +	case IRQF_TRIGGER_LOW: type = 3; break;
>  	default:
>  		type = 0;
>  	}
>  
> -	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
> -	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
> -	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
> -		desc->status |= IRQ_LEVEL;
> -
>  	ctrl_reg = in_be32(&intr->ctrl);
>  	ctrl_reg &= ~(0x3 << (22 - (l2irq * 2)));
>  	ctrl_reg |= (type << (22 - (l2irq * 2)));
>  	out_be32(&intr->ctrl, ctrl_reg);
>  
> +	__set_irq_handler_unlocked(virq, handler);
> +
>  	return 0;
>  }
>  
> @@ -241,6 +230,11 @@ static struct irq_chip mpc52xx_extirq_irqchip = {
>  /*
>   * Main interrupt irq_chip
>   */
> +static int mpc52xx_null_set_type(unsigned int virq, unsigned int flow_type)
> +{
> +	return 0; /* Do nothing so that the sense mask will get updated */
> +}
> +
>  static void mpc52xx_main_mask(unsigned int virq)
>  {
>  	int irq;
> @@ -268,6 +262,7 @@ static struct irq_chip mpc52xx_main_irqchip = {
>  	.mask = mpc52xx_main_mask,
>  	.mask_ack = mpc52xx_main_mask,
>  	.unmask = mpc52xx_main_unmask,
> +	.set_type = mpc52xx_null_set_type,
>  };
>  
>  /*
> @@ -300,6 +295,7 @@ static struct irq_chip mpc52xx_periph_irqchip = {
>  	.mask = mpc52xx_periph_mask,
>  	.mask_ack = mpc52xx_periph_mask,
>  	.unmask = mpc52xx_periph_unmask,
> +	.set_type = mpc52xx_null_set_type,
>  };
>  
>  /*
> @@ -343,9 +339,19 @@ static struct irq_chip mpc52xx_sdma_irqchip = {
>  	.mask = mpc52xx_sdma_mask,
>  	.unmask = mpc52xx_sdma_unmask,
>  	.ack = mpc52xx_sdma_ack,
> +	.set_type = mpc52xx_null_set_type,
>  };
>  
>  /**
> + * mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ
> + */
> +static int mpc52xx_is_extirq(int l1, int l2)
> +{
> +	return ((l1 == 0) && (l2 == 0)) ||
> +	       ((l1 == 1) && (l2 >= 1) && (l2 <= 3));
> +}
> +
> +/**
>   * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
>   */
>  static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
> @@ -363,38 +369,23 @@ static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
>  
>  	intrvect_l1 = (int)intspec[0];
>  	intrvect_l2 = (int)intspec[1];
> -	intrvect_type = (int)intspec[2];
> +	intrvect_type = (int)intspec[2] & 0x3;
>  
>  	intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) &
>  			 MPC52xx_IRQ_L1_MASK;
>  	intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK;
>  
> -	pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
> -		 intrvect_l2);
> -
>  	*out_hwirq = intrvect_linux;
> -	*out_flags = mpc52xx_map_senses[intrvect_type];
> +	*out_flags = IRQ_TYPE_LEVEL_LOW;
> +	if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2))
> +		*out_flags = mpc52xx_map_senses[intrvect_type];
>  
> +	pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
> +		 intrvect_l2);
>  	return 0;
>  }
>  
>  /**
> - * mpc52xx_irqx_gettype - determine the IRQ sense type (level/edge)
> - *
> - * Only external IRQs need this.
> - */
> -static int mpc52xx_irqx_gettype(int irq)
> -{
> -	int type;
> -	u32 ctrl_reg;
> -
> -	ctrl_reg = in_be32(&intr->ctrl);
> -	type = (ctrl_reg >> (22 - irq * 2)) & 0x3;
> -
> -	return mpc52xx_map_senses[type];
> -}
> -
> -/**
>   * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
>   */
>  static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
> @@ -402,68 +393,46 @@ static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
>  {
>  	int l1irq;
>  	int l2irq;
> -	struct irq_chip *good_irqchip;
> +	struct irq_chip *irqchip;
>  	void *good_handle;
>  	int type;
> +	u32 reg;
>  
>  	l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET;
>  	l2irq = irq & MPC52xx_IRQ_L2_MASK;
>  
>  	/*
> -	 * Most of ours IRQs will be level low
> -	 * Only external IRQs on some platform may be others
> +	 * External IRQs are handled differently by the hardware so they are
> +	 * handled by a dedicated irq_chip structure.
>  	 */
> -	type = IRQ_TYPE_LEVEL_LOW;
> +	if (mpc52xx_is_extirq(l1irq, l2irq)) {
> +		reg = in_be32(&intr->ctrl);
> +		type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3];
> +		if ((type == IRQ_TYPE_EDGE_FALLING) ||
> +		    (type == IRQ_TYPE_EDGE_RISING))
> +			good_handle = handle_edge_irq;
> +		else
> +			good_handle = handle_level_irq;
> +
> +		set_irq_chip_and_handler(virq, &mpc52xx_extirq_irqchip, good_handle);
> +		pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n",
> +			 __func__, l2irq, virq, (int)irq, type);
> +		return 0;
> +	}
>  
> +	/* It is an internal SOC irq.  Choose the correct irq_chip */
>  	switch (l1irq) {
> -	case MPC52xx_IRQ_L1_CRIT:
> -		pr_debug("%s: Critical. l2=%x\n", __func__, l2irq);
> -
> -		BUG_ON(l2irq != 0);
> -
> -		type = mpc52xx_irqx_gettype(l2irq);
> -		good_irqchip = &mpc52xx_extirq_irqchip;
> -		break;
> -
> -	case MPC52xx_IRQ_L1_MAIN:
> -		pr_debug("%s: Main IRQ[1-3] l2=%x\n", __func__, l2irq);
> -
> -		if ((l2irq >= 1) && (l2irq <= 3)) {
> -			type = mpc52xx_irqx_gettype(l2irq);
> -			good_irqchip = &mpc52xx_extirq_irqchip;
> -		} else {
> -			good_irqchip = &mpc52xx_main_irqchip;
> -		}
> -		break;
> -
> -	case MPC52xx_IRQ_L1_PERP:
> -		pr_debug("%s: Peripherals. l2=%x\n", __func__, l2irq);
> -		good_irqchip = &mpc52xx_periph_irqchip;
> -		break;
> -
> -	case MPC52xx_IRQ_L1_SDMA:
> -		pr_debug("%s: SDMA. l2=%x\n", __func__, l2irq);
> -		good_irqchip = &mpc52xx_sdma_irqchip;
> -		break;
> -
> +	case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break;
> +	case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
> +	case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
>  	default:
> -		pr_err("%s: invalid virq requested (0x%x)\n", __func__, virq);
> +		pr_err("%s: invalid irq: virq=%i, l1=%i, l2=%i\n",
> +		       __func__, virq, l1irq, l2irq);
>  		return -EINVAL;
>  	}
>  
> -	switch (type) {
> -	case IRQ_TYPE_EDGE_FALLING:
> -	case IRQ_TYPE_EDGE_RISING:
> -		good_handle = handle_edge_irq;
> -		break;
> -	default:
> -		good_handle = handle_level_irq;
> -	}
> -
> -	set_irq_chip_and_handler(virq, good_irqchip, good_handle);
> -
> -	pr_debug("%s: virq=%x, hw=%x. type=%x\n", __func__, virq,
> -		 (int)irq, type);
> +	set_irq_chip_and_handler(virq, irqchip, handle_level_irq);
> +	pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq);
>  
>  	return 0;
>  }
> @@ -502,6 +471,8 @@ void __init mpc52xx_init_irq(void)
>  		panic(__FILE__	": find_and_map failed on 'mpc5200-bestcomm'. "
>  				"Check node !");
>  
> +	pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr);
> +
>  	/* Disable all interrupt sources. */
>  	out_be32(&sdma->IntPend, 0xffffffff);	/* 1 means clear pending */
>  	out_be32(&sdma->IntMask, 0xffffffff);	/* 1 means disabled */
>

Patch

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index c0a9559..277c9c5 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -190,10 +190,10 @@  static void mpc52xx_extirq_ack(unsigned int virq)
 
 static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
 {
-	struct irq_desc *desc = get_irq_desc(virq);
 	u32 ctrl_reg, type;
 	int irq;
 	int l2irq;
+	void *handler = handle_level_irq;
 
 	irq = irq_map[virq].hwirq;
 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
@@ -201,32 +201,21 @@  static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
 	pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
 
 	switch (flow_type) {
-	case IRQF_TRIGGER_HIGH:
-		type = 0;
-		break;
-	case IRQF_TRIGGER_RISING:
-		type = 1;
-		break;
-	case IRQF_TRIGGER_FALLING:
-		type = 2;
-		break;
-	case IRQF_TRIGGER_LOW:
-		type = 3;
-		break;
+	case IRQF_TRIGGER_HIGH: type = 0; break;
+	case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
+	case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
+	case IRQF_TRIGGER_LOW: type = 3; break;
 	default:
 		type = 0;
 	}
 
-	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
-	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
-	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
-		desc->status |= IRQ_LEVEL;
-
 	ctrl_reg = in_be32(&intr->ctrl);
 	ctrl_reg &= ~(0x3 << (22 - (l2irq * 2)));
 	ctrl_reg |= (type << (22 - (l2irq * 2)));
 	out_be32(&intr->ctrl, ctrl_reg);
 
+	__set_irq_handler_unlocked(virq, handler);
+
 	return 0;
 }
 
@@ -241,6 +230,11 @@  static struct irq_chip mpc52xx_extirq_irqchip = {
 /*
  * Main interrupt irq_chip
  */
+static int mpc52xx_null_set_type(unsigned int virq, unsigned int flow_type)
+{
+	return 0; /* Do nothing so that the sense mask will get updated */
+}
+
 static void mpc52xx_main_mask(unsigned int virq)
 {
 	int irq;
@@ -268,6 +262,7 @@  static struct irq_chip mpc52xx_main_irqchip = {
 	.mask = mpc52xx_main_mask,
 	.mask_ack = mpc52xx_main_mask,
 	.unmask = mpc52xx_main_unmask,
+	.set_type = mpc52xx_null_set_type,
 };
 
 /*
@@ -300,6 +295,7 @@  static struct irq_chip mpc52xx_periph_irqchip = {
 	.mask = mpc52xx_periph_mask,
 	.mask_ack = mpc52xx_periph_mask,
 	.unmask = mpc52xx_periph_unmask,
+	.set_type = mpc52xx_null_set_type,
 };
 
 /*
@@ -343,9 +339,19 @@  static struct irq_chip mpc52xx_sdma_irqchip = {
 	.mask = mpc52xx_sdma_mask,
 	.unmask = mpc52xx_sdma_unmask,
 	.ack = mpc52xx_sdma_ack,
+	.set_type = mpc52xx_null_set_type,
 };
 
 /**
+ * mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ
+ */
+static int mpc52xx_is_extirq(int l1, int l2)
+{
+	return ((l1 == 0) && (l2 == 0)) ||
+	       ((l1 == 1) && (l2 >= 1) && (l2 <= 3));
+}
+
+/**
  * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
  */
 static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
@@ -363,38 +369,23 @@  static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
 
 	intrvect_l1 = (int)intspec[0];
 	intrvect_l2 = (int)intspec[1];
-	intrvect_type = (int)intspec[2];
+	intrvect_type = (int)intspec[2] & 0x3;
 
 	intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) &
 			 MPC52xx_IRQ_L1_MASK;
 	intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK;
 
-	pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
-		 intrvect_l2);
-
 	*out_hwirq = intrvect_linux;
-	*out_flags = mpc52xx_map_senses[intrvect_type];
+	*out_flags = IRQ_TYPE_LEVEL_LOW;
+	if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2))
+		*out_flags = mpc52xx_map_senses[intrvect_type];
 
+	pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
+		 intrvect_l2);
 	return 0;
 }
 
 /**
- * mpc52xx_irqx_gettype - determine the IRQ sense type (level/edge)
- *
- * Only external IRQs need this.
- */
-static int mpc52xx_irqx_gettype(int irq)
-{
-	int type;
-	u32 ctrl_reg;
-
-	ctrl_reg = in_be32(&intr->ctrl);
-	type = (ctrl_reg >> (22 - irq * 2)) & 0x3;
-
-	return mpc52xx_map_senses[type];
-}
-
-/**
  * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
  */
 static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
@@ -402,68 +393,46 @@  static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
 {
 	int l1irq;
 	int l2irq;
-	struct irq_chip *good_irqchip;
+	struct irq_chip *irqchip;
 	void *good_handle;
 	int type;
+	u32 reg;
 
 	l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET;
 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
 
 	/*
-	 * Most of ours IRQs will be level low
-	 * Only external IRQs on some platform may be others
+	 * External IRQs are handled differently by the hardware so they are
+	 * handled by a dedicated irq_chip structure.
 	 */
-	type = IRQ_TYPE_LEVEL_LOW;
+	if (mpc52xx_is_extirq(l1irq, l2irq)) {
+		reg = in_be32(&intr->ctrl);
+		type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3];
+		if ((type == IRQ_TYPE_EDGE_FALLING) ||
+		    (type == IRQ_TYPE_EDGE_RISING))
+			good_handle = handle_edge_irq;
+		else
+			good_handle = handle_level_irq;
+
+		set_irq_chip_and_handler(virq, &mpc52xx_extirq_irqchip, good_handle);
+		pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n",
+			 __func__, l2irq, virq, (int)irq, type);
+		return 0;
+	}
 
+	/* It is an internal SOC irq.  Choose the correct irq_chip */
 	switch (l1irq) {
-	case MPC52xx_IRQ_L1_CRIT:
-		pr_debug("%s: Critical. l2=%x\n", __func__, l2irq);
-
-		BUG_ON(l2irq != 0);
-
-		type = mpc52xx_irqx_gettype(l2irq);
-		good_irqchip = &mpc52xx_extirq_irqchip;
-		break;
-
-	case MPC52xx_IRQ_L1_MAIN:
-		pr_debug("%s: Main IRQ[1-3] l2=%x\n", __func__, l2irq);
-
-		if ((l2irq >= 1) && (l2irq <= 3)) {
-			type = mpc52xx_irqx_gettype(l2irq);
-			good_irqchip = &mpc52xx_extirq_irqchip;
-		} else {
-			good_irqchip = &mpc52xx_main_irqchip;
-		}
-		break;
-
-	case MPC52xx_IRQ_L1_PERP:
-		pr_debug("%s: Peripherals. l2=%x\n", __func__, l2irq);
-		good_irqchip = &mpc52xx_periph_irqchip;
-		break;
-
-	case MPC52xx_IRQ_L1_SDMA:
-		pr_debug("%s: SDMA. l2=%x\n", __func__, l2irq);
-		good_irqchip = &mpc52xx_sdma_irqchip;
-		break;
-
+	case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break;
+	case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
+	case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
 	default:
-		pr_err("%s: invalid virq requested (0x%x)\n", __func__, virq);
+		pr_err("%s: invalid irq: virq=%i, l1=%i, l2=%i\n",
+		       __func__, virq, l1irq, l2irq);
 		return -EINVAL;
 	}
 
-	switch (type) {
-	case IRQ_TYPE_EDGE_FALLING:
-	case IRQ_TYPE_EDGE_RISING:
-		good_handle = handle_edge_irq;
-		break;
-	default:
-		good_handle = handle_level_irq;
-	}
-
-	set_irq_chip_and_handler(virq, good_irqchip, good_handle);
-
-	pr_debug("%s: virq=%x, hw=%x. type=%x\n", __func__, virq,
-		 (int)irq, type);
+	set_irq_chip_and_handler(virq, irqchip, handle_level_irq);
+	pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq);
 
 	return 0;
 }
@@ -502,6 +471,8 @@  void __init mpc52xx_init_irq(void)
 		panic(__FILE__	": find_and_map failed on 'mpc5200-bestcomm'. "
 				"Check node !");
 
+	pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr);
+
 	/* Disable all interrupt sources. */
 	out_be32(&sdma->IntPend, 0xffffffff);	/* 1 means clear pending */
 	out_be32(&sdma->IntMask, 0xffffffff);	/* 1 means disabled */