Re: ISA -> ISA_ (Re: [GIT PATCH] ACPI patches for 2.6.25-rc6)

Alexey Starikovskiy
2008-03-26T19:21:50Z

Bjorn Helgaas wrote:
> On Wednesday 26 March 2008 11:24:41 am Alexey Starikovskiy wrote:
>
>> Bjorn Helgaas wrote:
>>
>>> I'm curious about how this works. I disassembled the DSDT from
>>> http://bugzilla.kernel.org/show_bug.cgi?id=4773 (I attached the disassembly
>>> at http://bugzilla.kernel.org/attachment.cgi?id=15448&action=view), and
>>> the _PRT contains "_SB" and "ISA" (no trailing underscores):
>>>
>>> Package (0x04)
>>> {
>>> 0x000DFFFF,
>>> 0x00,
>>> \_SB.PCI0.ISA.LNKA,
>>> 0x00
>>> }
>>>
>>> But by the time we get to acpi_pci_irq_add_entry(), we've added the
>>> underscores somewhere (see
>>> http://bugzilla.kernel.org/attachment.cgi?id=15423&action=view):
>>>
>>> 0000:00:0d[A] -> \_SB_.PCI0.ISA_.LNKA
>>>
>>> I don't know where this happens, but it certainly confused me, and
>>> it seems like it could lead to other bugs.
>>>
>>>
>> ACPI is supposed to add trailing underscore for pad all names to 4 bytes.
>> So ISA will be padded to ISA_.
>>
>
> The questions are "where does this happen?" and "why does it not
> apply to other things like asus_acpi.c?"
>
1. drivers/acpi/namespace/nsutils.c:419