Patchwork fix the interrupt loss problem on powerpc IPIC(2.6.25-2.6.28)

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Submitter dayu@datangmobile.cn
Date Feb. 18, 2009, 5:47 a.m.
Message ID <D728AD1FA2543948B89DE29C5BF4CD0716AF9623@bjmail1.bj.datangmobile.com>
Download mbox | patch
Permalink /patch/23328/
State Accepted
Delegated to: Kumar Gala
Headers show

Comments

dayu@datangmobile.cn - Feb. 18, 2009, 5:47 a.m.
renew description in  the patch,  with this change the 'temp'  is still used to make code clear.
Kumar Gala - Feb. 19, 2009, 4:41 p.m.
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

Patch

--- 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
@@ -592,8 +591,7 @@  static void ipic_mask_irq_and_ack(unsign
 	temp &= ~(1 << (31 - ipic_info[src].bit));
 	ipic_write(ipic->regs, ipic_info[src].mask, temp);

-	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