From: <dayu@datangmobile.cn>
To: <olof@lixom.net>
Cc: linuxppc-dev@ozlabs.org, leoli@freescale.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28)
Date: Wed, 18 Feb 2009 13:47:42 +0800 [thread overview]
Message-ID: <D728AD1FA2543948B89DE29C5BF4CD0716AF9623@bjmail1.bj.datangmobile.com> (raw)
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
next reply other threads:[~2009-02-18 5:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-18 5:47 dayu [this message]
2009-02-19 16:41 ` [PATCH] fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28) Kumar Gala
-- strict thread matches above, loose matches on Subject: below --
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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