[PATCH] powerpc: ipic - fix status get and status clear

[Christophe LEROY]

Le 19/10/2017 à 07:06, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy at c-s.fr> writes:
> 
>> IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
>> which is the mask register.
> 
> This seems like it would be a bad bug. But I guess it hasn't mattered
> for some reason?

As far as I can see, this function has been added in kernel 2.6.12 but 
has never been used in-tree.

I have discovered this error while implementing NMI watchdog on a 832x 
board, ie this function is needed to know when a machine check exception 
is generated by the watchdog timer.

Christophe

> 
> cheers
> 
>> diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
>> index 16f1edd78c40..535cf1f6941c 100644
>> --- a/arch/powerpc/sysdev/ipic.c
>> +++ b/arch/powerpc/sysdev/ipic.c
>> @@ -846,12 +846,12 @@ void ipic_disable_mcp(enum ipic_mcp_irq mcp_irq)
>>   
>>   u32 ipic_get_mcp_status(void)
>>   {
>> -	return ipic_read(primary_ipic->regs, IPIC_SERMR);
>> +	return ipic_read(primary_ipic->regs, IPIC_SERSR);
>>   }
>>   
>>   void ipic_clear_mcp_status(u32 mask)
>>   {
>> -	ipic_write(primary_ipic->regs, IPIC_SERMR, mask);
>> +	ipic_write(primary_ipic->regs, IPIC_SERSR, mask);
>>   }
>>   
>>   /* Return an interrupt vector or 0 if no interrupt is pending. */
>> -- 
>> 2.13.3