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* [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28)
@ 2009-02-18  2:16 dayu
  2009-02-18  2:43 ` Olof Johansson
  0 siblings, 1 reply; 4+ messages in thread
From: dayu @ 2009-02-18  2:16 UTC (permalink / raw)
  To: leoli, galak; +Cc: linuxppc-dev, linux-kernel

From: Da Yu <dayu@datangmobile•cn>
Date: Wed, 18 Feb 2009 19:58:20 +0800
Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC =
(2.6.25-2.6.28)

Signed-off-by: Da Yu <dayu@datangmobile•cn>
---

--- a/arch/powerpc/sysdev/ipic.c	2009-02-18 09:47:04.000000000 +0800
+++ b/arch/powerpc/sysdev/ipic.c	2009-02-18 09:46:34.000000000 +0800
@@ -568,8 +568,7 @@ static void ipic_ack_irq(unsigned int vi

 	spin_lock_irqsave(&ipic_lock, flags);

-	temp =3D ipic_read(ipic->regs, ipic_info[src].ack);
-	temp |=3D (1 << (31 - ipic_info[src].bit));
+	temp =3D 1 << (31 - ipic_info[src].bit);
 	ipic_write(ipic->regs, ipic_info[src].ack, temp);

 	/* mb() can't guarantee that ack is finished.  But it does finish
@@ -592,8 +591,7 @@ static void ipic_mask_irq_and_ack(unsign
 	temp &=3D ~(1 << (31 - ipic_info[src].bit));
 	ipic_write(ipic->regs, ipic_info[src].mask, temp);

-	temp =3D ipic_read(ipic->regs, ipic_info[src].ack);
-	temp |=3D (1 << (31 - ipic_info[src].bit));
+	temp =3D 1 << (31 - ipic_info[src].bit);
 	ipic_write(ipic->regs, ipic_info[src].ack, temp);

 	/* mb() can't guarantee that ack is finished.  But it does finish




-----=D3=CA=BC=FE=D4=AD=BC=FE-----
=B7=A2=BC=FE=C8=CB: Li Yang [mailto:leoli@freescale•com]=20
=B7=A2=CB=CD=CA=B1=BC=E4: 2009=C4=EA2=D4=C217=C8=D5 22:38
=CA=D5=BC=FE=C8=CB: Kumar Gala
=B3=AD=CB=CD: =F3=CE=D3=ED; linux-kernel@vger•kernel.org; =
linuxppc-dev@ozlabs•org
=D6=F7=CC=E2: Re: [PATCH] fix the interrupt loss problem on powerpc IPIC =
(2.6.23)

On Tue, Feb 17, 2009 at 10:12 PM, Kumar Gala <galak@kernel•crashing.org> =
wrote:
>
> On Feb 17, 2009, at 6:44 AM, <dayu@datangmobile•cn>=20
> <dayu@datangmobile•cn>
> wrote:
>
>> From: Da Yu <dayu@datangmobile•cn>
>> Date: Tue, 17 Feb 2009 19:58:20 +0800
>> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC=20
>> (2.6.23)
>>
>> Signed-off-by: Da Yu <dayu@datangmobile•cn>
>> ---
>
> Please provide a bit more description as to why this fixes the issue.

The pending register is write 1 clear.  If there are more than one =
external interrupts pending at the same time, acking the first interrupt =
will also clear other interrupt pending bits.  That will cause loss of =
interrupt.

- Leo

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28)
  2009-02-18  2:16 [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28) dayu
@ 2009-02-18  2:43 ` Olof Johansson
  0 siblings, 0 replies; 4+ messages in thread
From: Olof Johansson @ 2009-02-18  2:43 UTC (permalink / raw)
  To: dayu; +Cc: linuxppc-dev, leoli, linux-kernel

On Wed, Feb 18, 2009 at 10:16:07AM +0800, dayu@datangmobile•cn wrote:
> From: Da Yu <dayu@datangmobile•cn>
> Date: Wed, 18 Feb 2009 19:58:20 +0800
> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28)
> 
> Signed-off-by: Da Yu <dayu@datangmobile•cn>

Still no proper explanation in the patch.

Also, with this change, is 'temp' really needed, or can you just pass in the
mask by hand?


-Olof

> ---
> 
> --- a/arch/powerpc/sysdev/ipic.c	2009-02-18 09:47:04.000000000 +0800
> +++ b/arch/powerpc/sysdev/ipic.c	2009-02-18 09:46:34.000000000 +0800
> @@ -568,8 +568,7 @@ static void ipic_ack_irq(unsigned int vi
> 
>  	spin_lock_irqsave(&ipic_lock, flags);
> 
> -	temp = ipic_read(ipic->regs, ipic_info[src].ack);
> -	temp |= (1 << (31 - ipic_info[src].bit));
> +	temp = 1 << (31 - ipic_info[src].bit);
>  	ipic_write(ipic->regs, ipic_info[src].ack, temp);
> 
>  	/* mb() can't guarantee that ack is finished.  But it does finish

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28)
@ 2009-02-18  5:47 dayu
  2009-02-19 16:41 ` Kumar Gala
  0 siblings, 1 reply; 4+ messages in thread
From: dayu @ 2009-02-18  5:47 UTC (permalink / raw)
  To: olof; +Cc: linuxppc-dev, leoli, linux-kernel

renew description in  the patch,  with this change the 'temp'  is still =
used to make code clear.

___________________________________________

From: Da Yu <dayu@datangmobile•cn>
Date: Wed, 18 Feb 2009 19:58:20 +0800
Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC =
(2.6.25-2.6.28)

Description: The interrupt pending register is write 1 clear.  If there =
are more than one external interrupts pending at the same time, acking =
the first interrupt by reading pending register then OR the =
corresponding bit and write back to pending register will also clear =
other interrupt pending bits.  That will cause loss of interrupt.

Signed-off-by: Da Yu <dayu@datangmobile•cn>
---

--- a/arch/powerpc/sysdev/ipic.c	2009-02-18 09:47:04.000000000 +0800
+++ b/arch/powerpc/sysdev/ipic.c	2009-02-18 09:46:34.000000000 +0800
@@ -568,8 +568,7 @@ static void ipic_ack_irq(unsigned int vi

 	spin_lock_irqsave(&ipic_lock, flags);

-	temp =3D ipic_read(ipic->regs, ipic_info[src].ack);
-	temp |=3D (1 << (31 - ipic_info[src].bit));
+	temp =3D 1 << (31 - ipic_info[src].bit);
 	ipic_write(ipic->regs, ipic_info[src].ack, temp);

 	/* mb() can't guarantee that ack is finished.  But it does finish
@@ -592,8 +591,7 @@ static void ipic_mask_irq_and_ack(unsign
 	temp &=3D ~(1 << (31 - ipic_info[src].bit));
 	ipic_write(ipic->regs, ipic_info[src].mask, temp);

-	temp =3D ipic_read(ipic->regs, ipic_info[src].ack);
-	temp |=3D (1 << (31 - ipic_info[src].bit));
+	temp =3D 1 << (31 - ipic_info[src].bit);
 	ipic_write(ipic->regs, ipic_info[src].ack, temp);

 	/* mb() can't guarantee that ack is finished.  But it does finish



=20
=20

-----=D3=CA=BC=FE=D4=AD=BC=FE-----
=B7=A2=BC=FE=C8=CB: Olof Johansson [mailto:olof@lixom•net]=20
=B7=A2=CB=CD=CA=B1=BC=E4: 2009=C4=EA2=D4=C218=C8=D5 10:43
=CA=D5=BC=FE=C8=CB: =F3=CE=D3=ED
=B3=AD=CB=CD: leoli@freescale•com; galak@kernel•crashing.org; =
linuxppc-dev@ozlabs•org; linux-kernel@vger•kernel.org
=D6=F7=CC=E2: Re: [PATCH] fix the interrupt loss problem on powerpc =
IPIC(2.6.25-2.6.28)

On Wed, Feb 18, 2009 at 10:16:07AM +0800, dayu@datangmobile•cn wrote:
> From: Da Yu <dayu@datangmobile•cn>
> Date: Wed, 18 Feb 2009 19:58:20 +0800
> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC=20
> (2.6.25-2.6.28)
>=20
> Signed-off-by: Da Yu <dayu@datangmobile•cn>

Still no proper explanation in the patch.

Also, with this change, is 'temp' really needed, or can you just pass in =
the mask by hand?


-Olof

> ---
>=20
> --- a/arch/powerpc/sysdev/ipic.c	2009-02-18 09:47:04.000000000 +0800
> +++ b/arch/powerpc/sysdev/ipic.c	2009-02-18 09:46:34.000000000 +0800
> @@ -568,8 +568,7 @@ static void ipic_ack_irq(unsigned int vi
>=20
>  	spin_lock_irqsave(&ipic_lock, flags);
>=20
> -	temp =3D ipic_read(ipic->regs, ipic_info[src].ack);
> -	temp |=3D (1 << (31 - ipic_info[src].bit));
> +	temp =3D 1 << (31 - ipic_info[src].bit);
>  	ipic_write(ipic->regs, ipic_info[src].ack, temp);
>=20
>  	/* mb() can't guarantee that ack is finished.  But it does finish

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28)
  2009-02-18  5:47 [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28) dayu
@ 2009-02-19 16:41 ` Kumar Gala
  0 siblings, 0 replies; 4+ messages in thread
From: Kumar Gala @ 2009-02-19 16:41 UTC (permalink / raw)
  To: <dayu@datangmobile•cn>; +Cc: olof, linuxppc-dev, leoli, linux-kernel


On Feb 17, 2009, at 11:47 PM, <dayu@datangmobile•cn> <dayu@datangmobile•cn 
 > wrote:

>
> From: Da Yu <dayu@datangmobile•cn>
> Date: Wed, 18 Feb 2009 19:58:20 +0800
> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC  
> (2.6.25-2.6.28)
>
> Description: The interrupt pending register is write 1 clear.  If  
> there are more than one external interrupts pending at the same  
> time, acking the first interrupt by reading pending register then OR  
> the corresponding bit and write back to pending register will also  
> clear other interrupt pending bits.  That will cause loss of  
> interrupt.
>
> Signed-off-by: Da Yu <dayu@datangmobile•cn>
> ---


applied to next

- k

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2009-02-19 16:41 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2009-02-18  2:16 [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28) dayu
2009-02-18  2:43 ` Olof Johansson
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2009-02-18  5:47 [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28) dayu
2009-02-19 16:41 ` Kumar Gala

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