On Friday, January 07, 2011 04:29:00 pm Jiri Slaby wrote: > On 01/08/2011 12:03 AM, Bjorn Helgaas wrote: > > On Friday, January 07, 2011 01:44:35 pm Jiri Slaby wrote: > >> On 01/06/2011 08:24 PM, Bjorn Helgaas wrote: > >>> Theoretically, ACPI tells us about the GPIO/TCO/etc. regions in a > >>> generic way via namespace devices or something in the static tables. > >>> Is that generic information missing, or is it there and Linux is > >>> ignoring it? If we're ignoring it, I'd rather fix that. > >> > >> It works for most boxes I would say. Try to google for "claimed by ICH4 > >> ACPI/GPIO/TCO", it reports sane ranges like 0400-047f or 4000-407f. > > > > My point is that BIOS should be telling the OS about GPIO/TCO/etc. > > regions via an ACPI mechanism, and, ideally, we would use that rather > > than reading the address out of chipset-dependent registers. > > > > Even though PMBASE says the ACPI registers occupy 128 bytes from > > 0x100-0x17f, it's likely there's no actual conflict between the > > last 16 bytes and the IDE device. > > I wouldn't say so. According to the datasheet 0x60-0x7f of the space > (i.e. 0x160-0x17f here) is for TCO registers. There: > 0x10 -- Software IRQ Generation Register (i.e. 0x170) > 0x11-0x1f -- reserved (0x171-0x17f) > > So at least 0x170 should be conflicting. Unless TCO is unused/disabled > and not mapped there at all. May be that the case? Maybe. All your patch does is avoid reserving this 0x100-0x1f7 region; it doesn't actually *move* anything. And the IDE device apparently works at the 0x170 compatibility address. So the ICH ACPI stuff is still at 0x100-0x17f, so apparently they don't conflict or maybe the ICH ACPI stuff is disabled. If the box doesn't even have ACPI, I suppose there would be no reason to have the ACPI registers enabled. Is there something in ICH that tells us whether they're enabled? > > ACPI probably reports this region via the FADT (the GPE PM register > > blocks) and possibly a PNP0C02 device. These will probably report > > something that doesn't conflict with the legacy IDE ports, i.e., a > > subset of the 0x100-0x17f range. > > > > Ooooh, I notice in the bugzilla that something's wrong with SMBIOS > > (comment 29) and ACPI is disabled because we couldn't find the > > RSDP (dmesg in comment 27). What sort of machine is this, anyway? > > We didn't find PNPBIOS, either. > > Hmm, it looks like some old crap. What exact information you would like > to know? I've just asked if ACPI is not disabled in BIOS. There should > be no machine without ACPI running still in the 21st century, I think. I'm just wondering if the machine actually does have ACPI, but there's some Linux problem related to finding the tables. If it's really old enough, that wouldn't be so surprising, but I see USB and gigabit NIC hardware, so it's not truly ancient. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
