[04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of redundant mpic_irq_set_wake

Message ID 1442850433-5903-5-git-send-email-sudeep.holla@arm.com
State New
Headers show

Commit Message

Sudeep Holla Sept. 21, 2015, 3:47 p.m.
mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
as it doesn't guarantee wakeup for that interrupt.

This patch removes the redundant mpic_irq_set_wake and sets the
IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Hongtao Jia <hongtao.jia@freescale.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 arch/powerpc/sysdev/mpic.c | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

Comments

Scott Wood Sept. 22, 2015, 11:50 p.m. | #1
On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> as it doesn't guarantee wakeup for that interrupt.
> 
> This patch removes the redundant mpic_irq_set_wake and sets the
> IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.
> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Scott Wood <scottwood@freescale.com>
> Cc: Hongtao Jia <hongtao.jia@freescale.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  arch/powerpc/sysdev/mpic.c | 23 ++++-------------------
>  1 file changed, 4 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
> index 537e5db85a06..123e43612f0a 100644
> --- a/arch/powerpc/sysdev/mpic.c
> +++ b/arch/powerpc/sysdev/mpic.c
> @@ -924,22 +924,6 @@ int mpic_set_irq_type(struct irq_data *d, unsigned int 
> flow_type)
>       return IRQ_SET_MASK_OK_NOCOPY;
>  }
>  
> -static int mpic_irq_set_wake(struct irq_data *d, unsigned int on)
> -{
> -     struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
> -     struct mpic *mpic = mpic_from_irq_data(d);
> -
> -     if (!(mpic->flags & MPIC_FSL))
> -             return -ENXIO;
> -
> -     if (on)
> -             desc->action->flags |= IRQF_NO_SUSPEND;
> -     else
> -             desc->action->flags &= ~IRQF_NO_SUSPEND;
> -
> -     return 0;
> -}
> -
>  void mpic_set_vector(unsigned int virq, unsigned int vector)
>  {
>       struct mpic *mpic = mpic_from_irq(virq);
> @@ -977,7 +961,6 @@ static struct irq_chip mpic_irq_chip = {
>       .irq_unmask     = mpic_unmask_irq,
>       .irq_eoi        = mpic_end_irq,
>       .irq_set_type   = mpic_set_irq_type,
> -     .irq_set_wake   = mpic_irq_set_wake,
>  };
>  
>  #ifdef CONFIG_SMP
> @@ -992,7 +975,6 @@ static struct irq_chip mpic_tm_chip = {
>       .irq_mask       = mpic_mask_tm,
>       .irq_unmask     = mpic_unmask_tm,
>       .irq_eoi        = mpic_end_irq,
> -     .irq_set_wake   = mpic_irq_set_wake,
>  };
>  
>  #ifdef CONFIG_MPIC_U3_HT_IRQS
> @@ -1283,8 +1265,11 @@ struct mpic * __init mpic_alloc(struct device_node 
> *node,
>               flags |= MPIC_NO_RESET;
>       if (of_get_property(node, "single-cpu-affinity", NULL))
>               flags |= MPIC_SINGLE_DEST_CPU;
> -     if (of_device_is_compatible(node, "fsl,mpic"))
> +     if (of_device_is_compatible(node, "fsl,mpic")) {
>               flags |= MPIC_FSL | MPIC_LARGE_VECTORS;
> +             mpic_irq_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
> +             mpic_tm_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
> +     }

What difference does IRQCHIP_SKIP_SET_WAKE make in the absence of an 
.irq_set_wake() callback?

This is basically repealing commit 5ff04b7287d87c1db7 ("powerpc/mpic: add 
irq_set_wake support").  Wang Dongsheng, can you explain why that patch was 
needed?

-Scott

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Dongsheng Wang Sept. 23, 2015, 2:35 a.m. | #2
> -----Original Message-----

> From: Wood Scott-B07421

> Sent: Wednesday, September 23, 2015 7:50 AM

> To: Sudeep Holla

> Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; Thomas Gleixner;

> Rafael J. Wysocki; Benjamin Herrenschmidt; Paul Mackerras; Michael Ellerman; Jia

> Hongtao-B38951; Marc Zyngier; linuxppc-dev@lists.ozlabs.org; Wang Dongsheng-

> B40534

> Subject: Re: [PATCH 04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of

> redundant mpic_irq_set_wake

> 

> On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:

> > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND

> > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak

> > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag

> > as it doesn't guarantee wakeup for that interrupt.

> >


Non-freescale return -ENXIO, is there any issue? If non-freescale platform does
not support it, but IPs still use enable/disable_irq_wake, we should return a error number.

IRQCHIP_SKIP_SET_WAKE just skip this feature, this is not our expected.
If non-freescale platform need this flag to skip this feature, it should be add
in self platform.

@Scott:
If set this flag we cannot keep a irq as a wakeup source when system going to
SUSPEND or MEM.

irq_set_wake() means we can set this irq as a wake source.
IRQCHIP_SKIP_SET_WAKE is ignore irq_set_wake() feature.

Regards,
-Dongsheng
Thomas Gleixner Sept. 23, 2015, 3:49 a.m. | #3
On Wed, 23 Sep 2015, Wang Dongsheng wrote:
> > On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> > > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> > > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> > > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> > > as it doesn't guarantee wakeup for that interrupt.
> > >
> 
> Non-freescale return -ENXIO, is there any issue? If non-freescale
> platform does not support it, but IPs still use
> enable/disable_irq_wake, we should return a error number.

You can just set IRQCHIP_SKIP_SET_WAKE for FSL chips and not for the
others.

> @Scott:
> If set this flag we cannot keep a irq as a wakeup source when system going to
> SUSPEND or MEM.
> 
> irq_set_wake() means we can set this irq as a wake source.
> IRQCHIP_SKIP_SET_WAKE is ignore irq_set_wake() feature.

Nonsense. IRQCHIP_SKIP_SET_WAKE merily tells the core not to bail on
!chip->irq_set_wake(), but its still marking the interrupt as wakeup
source and therefor not masking it on suspend.

IRQF_NO_SUSPEND is the wrong tool. End of story.

Thanks,

	tglx
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Scott Wood Sept. 23, 2015, 4:06 a.m. | #4
On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> as it doesn't guarantee wakeup for that interrupt.
> 
> This patch removes the redundant mpic_irq_set_wake and sets the
> IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.
> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Scott Wood <scottwood@freescale.com>
> Cc: Hongtao Jia <hongtao.jia@freescale.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  arch/powerpc/sysdev/mpic.c | 23 ++++-------------------
>  1 file changed, 4 insertions(+), 19 deletions(-)

Acked-by: Scott Wood <scottwood@freescale.com>

-Scott

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Dongsheng Wang Sept. 23, 2015, 5:31 a.m. | #5
> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
> owner@vger.kernel.org] On Behalf Of Thomas Gleixner
> Sent: Wednesday, September 23, 2015 11:49 AM
> To: Wang Dongsheng-B40534
> Cc: Wood Scott-B07421; Sudeep Holla; linux-pm@vger.kernel.org; linux-
> kernel@vger.kernel.org; Rafael J. Wysocki; Benjamin Herrenschmidt; Paul
> Mackerras; Michael Ellerman; Jia Hongtao-B38951; Marc Zyngier; linuxppc-
> dev@lists.ozlabs.org
> Subject: RE: [PATCH 04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of
> redundant mpic_irq_set_wake
> 
> On Wed, 23 Sep 2015, Wang Dongsheng wrote:
> > > On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> > > > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> > > > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> > > > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> > > > as it doesn't guarantee wakeup for that interrupt.
> > > >
> >
> > Non-freescale return -ENXIO, is there any issue? If non-freescale
> > platform does not support it, but IPs still use
> > enable/disable_irq_wake, we should return a error number.
> 
> You can just set IRQCHIP_SKIP_SET_WAKE for FSL chips and not for the
> others.
> 
> > @Scott:
> > If set this flag we cannot keep a irq as a wakeup source when system going to
> > SUSPEND or MEM.
> >
> > irq_set_wake() means we can set this irq as a wake source.
> > IRQCHIP_SKIP_SET_WAKE is ignore irq_set_wake() feature.
> 
> Nonsense. IRQCHIP_SKIP_SET_WAKE merily tells the core not to bail on
> !chip->irq_set_wake(), but its still marking the interrupt as wakeup
> source and therefor not masking it on suspend.
> 

Sorry, I just check irq_set_irq_wake() code, right, IRQCHIP_SKIP_SET_WAKE also can
going to irqd_set to mask IRQD_WAKEUP_STATE.

Yes, this flag just skip the irq_set_wake() not this feature.

Regards,
-Dongsheng

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Thomas Gleixner Sept. 23, 2015, 8 a.m. | #6
On Wed, 23 Sep 2015, Wang Dongsheng wrote:
> > -----Original Message-----
> > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
> > owner@vger.kernel.org] On Behalf Of Thomas Gleixner
> > Sent: Wednesday, September 23, 2015 11:49 AM
> > To: Wang Dongsheng-B40534
> > Cc: Wood Scott-B07421; Sudeep Holla; linux-pm@vger.kernel.org; linux-
> > kernel@vger.kernel.org; Rafael J. Wysocki; Benjamin Herrenschmidt; Paul
> > Mackerras; Michael Ellerman; Jia Hongtao-B38951; Marc Zyngier; linuxppc-
> > dev@lists.ozlabs.org
> > Subject: RE: [PATCH 04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of
> > redundant mpic_irq_set_wake

Can you please fix you mail client to get rid of that silly copy of
the mail header?

> > On Wed, 23 Sep 2015, Wang Dongsheng wrote:
> > > > On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> > > > > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> > > > > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> > > > > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> > > > > as it doesn't guarantee wakeup for that interrupt.
> > > > >
> > >
> > > Non-freescale return -ENXIO, is there any issue? If non-freescale
> > > platform does not support it, but IPs still use
> > > enable/disable_irq_wake, we should return a error number.
> > 
> > You can just set IRQCHIP_SKIP_SET_WAKE for FSL chips and not for the
> > others.
> > 
> > > @Scott:
> > > If set this flag we cannot keep a irq as a wakeup source when system going to
> > > SUSPEND or MEM.
> > >
> > > irq_set_wake() means we can set this irq as a wake source.
> > > IRQCHIP_SKIP_SET_WAKE is ignore irq_set_wake() feature.
> > 
> > Nonsense. IRQCHIP_SKIP_SET_WAKE merily tells the core not to bail on
> > !chip->irq_set_wake(), but its still marking the interrupt as wakeup
> > source and therefor not masking it on suspend.
> > 
> 
> Sorry, I just check irq_set_irq_wake() code, right, IRQCHIP_SKIP_SET_WAKE also can
> going to irqd_set to mask IRQD_WAKEUP_STATE.
> 
> Yes, this flag just skip the irq_set_wake() not this feature.

And just for completeness. That commit 5ff04b7287d87c 'powerpc/mpic:
add irq_set_wake support' is another example of trainwreck engineering.

    desc->action->flags |= IRQF_NO_SUSPEND;

This is not only horribly avoiding any of the existing APIs, it's also
broken as hell. desc->action can be NULL when that is called.

It seems fleascale is hell bent to fiddle with the guts of the core
code mindlessly. See commit c866cda47f2c

Yours grumpy

      tglx


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Sudeep Holla Oct. 19, 2015, 5:35 p.m. | #7
Hi Ben,

On 23/09/15 05:06, Scott Wood wrote:
> On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
>> mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
>> flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
>> is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
>> as it doesn't guarantee wakeup for that interrupt.
>>
>> This patch removes the redundant mpic_irq_set_wake and sets the
>> IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.
>>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Scott Wood <scottwood@freescale.com>
>> Cc: Hongtao Jia <hongtao.jia@freescale.com>
>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
>> ---
>>   arch/powerpc/sysdev/mpic.c | 23 ++++-------------------
>>   1 file changed, 4 insertions(+), 19 deletions(-)
>
> Acked-by: Scott Wood <scottwood@freescale.com>
>

Can you pick this up via your tree ?
Scott Wood Oct. 19, 2015, 5:46 p.m. | #8
On Mon, 2015-10-19 at 18:35 +0100, Sudeep Holla wrote:
> Hi Ben,
> 
> On 23/09/15 05:06, Scott Wood wrote:
> > On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> > > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets 
> > > IRQF_NO_SUSPEND
> > > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> > > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> > > as it doesn't guarantee wakeup for that interrupt.
> > > 
> > > This patch removes the redundant mpic_irq_set_wake and sets the
> > > IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.
> > > 
> > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > > Cc: Paul Mackerras <paulus@samba.org>
> > > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > > Cc: Scott Wood <scottwood@freescale.com>
> > > Cc: Hongtao Jia <hongtao.jia@freescale.com>
> > > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > > Cc: linuxppc-dev@lists.ozlabs.org
> > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> > > ---
> > >   arch/powerpc/sysdev/mpic.c | 23 ++++-------------------
> > >   1 file changed, 4 insertions(+), 19 deletions(-)
> > 
> > Acked-by: Scott Wood <scottwood@freescale.com>
> > 
> 
> Can you pick this up via your tree ?

OK.

-Scott

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Patch

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 537e5db85a06..123e43612f0a 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -924,22 +924,6 @@  int mpic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 	return IRQ_SET_MASK_OK_NOCOPY;
 }
 
-static int mpic_irq_set_wake(struct irq_data *d, unsigned int on)
-{
-	struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
-	struct mpic *mpic = mpic_from_irq_data(d);
-
-	if (!(mpic->flags & MPIC_FSL))
-		return -ENXIO;
-
-	if (on)
-		desc->action->flags |= IRQF_NO_SUSPEND;
-	else
-		desc->action->flags &= ~IRQF_NO_SUSPEND;
-
-	return 0;
-}
-
 void mpic_set_vector(unsigned int virq, unsigned int vector)
 {
 	struct mpic *mpic = mpic_from_irq(virq);
@@ -977,7 +961,6 @@  static struct irq_chip mpic_irq_chip = {
 	.irq_unmask	= mpic_unmask_irq,
 	.irq_eoi	= mpic_end_irq,
 	.irq_set_type	= mpic_set_irq_type,
-	.irq_set_wake	= mpic_irq_set_wake,
 };
 
 #ifdef CONFIG_SMP
@@ -992,7 +975,6 @@  static struct irq_chip mpic_tm_chip = {
 	.irq_mask	= mpic_mask_tm,
 	.irq_unmask	= mpic_unmask_tm,
 	.irq_eoi	= mpic_end_irq,
-	.irq_set_wake	= mpic_irq_set_wake,
 };
 
 #ifdef CONFIG_MPIC_U3_HT_IRQS
@@ -1283,8 +1265,11 @@  struct mpic * __init mpic_alloc(struct device_node *node,
 		flags |= MPIC_NO_RESET;
 	if (of_get_property(node, "single-cpu-affinity", NULL))
 		flags |= MPIC_SINGLE_DEST_CPU;
-	if (of_device_is_compatible(node, "fsl,mpic"))
+	if (of_device_is_compatible(node, "fsl,mpic")) {
 		flags |= MPIC_FSL | MPIC_LARGE_VECTORS;
+		mpic_irq_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
+		mpic_tm_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
+	}
 
 	mpic = kzalloc(sizeof(struct mpic), GFP_KERNEL);
 	if (mpic == NULL)