Re: [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.23)

[Kumar Gala <galak@kernel.crashing.org>]

On Feb 17, 2009, at 6:44 AM, <dayu@datangmobile.cn> <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  
> (2.6.23)
>
> Signed-off-by: Da Yu <dayu@datangmobile.cn>
> ---

Please provide a bit more description as to why this fixes the issue.

- k

>
>
> --- a/arch/powerpc/sysdev/ipic.c	2009-02-17 15:10:18.000000000 +0800
> +++ b/arch/powerpc/sysdev/ipic.c	2009-02-17 20:05:28.000000000 +0800
> @@ -561,8 +561,7 @@ static void ipic_ack_irq(unsigned int vi
>
> 	spin_lock_irqsave(&ipic_lock, flags);
>
> -	temp = ipic_read(ipic->regs, ipic_info[src].pend);
> -	temp |= (1 << (31 - ipic_info[src].bit));
> +	temp = 1 << (31 - ipic_info[src].bit);
> 	ipic_write(ipic->regs, ipic_info[src].pend, temp);
>
> 	spin_unlock_irqrestore(&ipic_lock, flags);
> @@ -581,8 +580,7 @@ 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].pend);
> -	temp |= (1 << (31 - ipic_info[src].bit));
> +	temp = 1 << (31 - ipic_info[src].bit);
> 	ipic_write(ipic->regs, ipic_info[src].pend, temp);
>
> 	spin_unlock_irqrestore(&ipic_lock, flags);