答复: [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.25-2.6.28)

From: Da Yu <redacted>
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 <redacted>
---

--- 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

-----=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 [off-list ref] =
wrote:

On Feb 17, 2009, at 6:44 AM, [off-list ref]=20
[off-list ref]
wrote:

quoted

From: Da Yu <redacted>
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 <redacted>
---

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