On Saturday, January 08, 2011 02:58:01 am Jiri Slaby wrote: > On 01/08/2011 01:16 AM, Bjorn Helgaas wrote: > > 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? > > Hmm, there is: > bit 4: ACPI Enable (ACPI_EN) â R/W. > 0 = Disable. > 1 = Decode of the I/O range pointed to by the ACPI Base register is > enabled, and the ACPI power management function is enabled. Note that > the APM power management ranges (B2/B3h) are always enabled and are not > affected by this bit. > > at 0x44 in the bridge conf space. So we should definitely check the value. > > I don't have the actual value in that register when ACPI is disabled in > BIOS. From the run where acpi=off was passed to the kernel, there is > 0x10 (i.e. ACPI_EN=1). However I don't know whether ACPI was disabled in > BIOS at that time. Checking ACPI_EN before doing anything in the quirk looks like the simplest thing (if the BIOS actually sets ACPI_EN=0 when it disables ACPI). Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
