Re: [PATCH] x86: update_mptable need pci_routeirq

[Yinghai Lu <yinghai@kernel.org>]

Bjorn Helgaas wrote:
> On Friday 15 May 2009 01:51:56 pm Yinghai Lu wrote:
>> to get all device irq routing and save them
> 
> This changelog isn't really enough for me to understand
> what's going on.
> 
>> Index: linux-2.6/arch/x86/kernel/mpparse.c
>> ===================================================================
>> --- linux-2.6.orig/arch/x86/kernel/mpparse.c
>> +++ linux-2.6/arch/x86/kernel/mpparse.c
>> @@ -17,6 +17,7 @@
>>  #include <linux/acpi.h>
>>  #include <linux/module.h>
>>  #include <linux/smp.h>
>> +#include <linux/pci.h>
>>  
>>  #include <asm/mtrr.h>
>>  #include <asm/mpspec.h>
>> @@ -961,6 +962,7 @@ static int __initdata enable_update_mpta
>>  static int __init update_mptable_setup(char *str)
>>  {
>>  	enable_update_mptable = 1;
>> +	pci_routeirq = 1;
> 
> I hate to see new uses of pci_routeirq.  It'd be nice to remove it
> completely someday.  But maybe it can't be helped.
> 
>>  	return 0;
>>  }
>>  early_param("update_mptable", update_mptable_setup);
> 
> "update_mptable" is apparently a boot option, but it's not mentioned
> in Documentation/kernel-parameters.txt.  Is this some sort of debug
> code or BIOS-writer's helper?  Same with "alloc_mptable".  Why do
> we have this stuff?
> 

1. kexec path: after acpi kernel and use kexec to load kerenl with mptable support only or acpi=off
2. help to BIOS engineer to understand how to set mptable and irq routing setup by chipset.
   esp system have several cards and there is bridge in those cards.

YH