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

Alexey Starikovskiy
2008-03-26T17:24:52Z

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_.

Regards,
Alex.