[coreboot] [RFH] Status of the Lenovo X201

[Nico Huber]

On 02.05.2018 00:03, qtux wrote:
> ...
> ACPI Warning: SystemIO range 0x0000000000000480-0x00000000000004AF
> conflicts with OpRegion 0x0000000000000480-0x00000000000004EB (\GPIO)
> (20180105/utaddress-247)
> ACPI: If an ACPI driver is available for this device, you should use it
> instead of the native driver
> lpc_ich: Resource conflict(s) found affecting gpio_ich
> 
> Maybe these are also caused by copy pasting Sandy Bridge code as I found
> a reference to PMIO and GPIO with matching addresses in
> src/southbridge/intel/bd82x6x/acpi/pch.asl. Do you have any ideas on
> this issue?

It's pretty simple. When the firmware was written (both coreboot and the
one from Lenovo) this `lpc_ich` driver didn't exist in Linux and wasn't
accounted for. From a firmware point of view, that driver shouldn't
exist at all and our ACPI code claims the device's resources therefore.
I don't think the driver was meant to be included into generic Linux
distributions.

Related story: The same applies to other drivers like the buggy intel-
spi. That one even warns in Kconfig "Say N here unless you know what you
are doing.". Due to a simple off-by-one in the code, it bricked[1] a lot
of systems with Ubuntu 17.10 and they had to withdraw their images.
That's what you get when you blindly enable all modules and ship them to
humble users.

Well, you better know what you are doing ;)

Nico

[1] It only write-protected the firmware flash by accident, the actual
    brick was caused by the UEFI shipping on the affected systems.