ACPI exception with 2.6.29-rc6

ACPI exception with 2.6.29-rc6

[Heinz Diehl]

Hi,

booting 2.6.29-rc6 shows the following in boot.log:

[....]
<7>bus: 00 index 4 mmio: [230000000, fcffffffff]
<6>ACPI: bus type pci registered
<5>PCI: MCFG configuration 0: base f0000000 segment 0 buses 0 - 127
<5>PCI: MCFG area at f0000000 reserved in E820
<6>PCI: Using MMCONFIG at f0000000 - f7ffffff
<6>PCI: Using configuration type 1 for base access
<4>bio: create slab <bio-0> at 0
<7>ACPI: EC: Look up EC in DSDT
--> <3>ACPI: Denied BIOS AML access to invalid port 0x4d0+0x2 (ELCR)
--> <4>ACPI Exception (dsopcode-0419): AE_AML_ILLEGAL_ADDRESS, During address validation of OpRegion [ELCR] [20081204]
<6>ACPI: Interpreter enabled
<6>ACPI: (supports S0 S1 S5)
<6>ACPI: Using IOAPIC for interrupt routing
<6>ACPI: No dock devices found.
<6>ACPI: PCI Root Bridge [PCI0] (0000:00)
<7>pci 0000:00:01.1: reg 10 io port: [0xe800-0xe83f]
[....]

...while 2.6.28.7 boots without showing any ACPI exception:

[....]
<7>bus: 00 index 3 mmio: [d0000000, efffffff]
<7>bus: 00 index 4 mmio: [230000000, fcffffffff]
<6>ACPI: bus type pci registered
<5>PCI: MCFG configuration 0: base f0000000 segment 0 buses 0 - 127
<5>PCI: MCFG area at f0000000 reserved in E820
<6>PCI: Using MMCONFIG at f0000000 - f7ffffff
<6>PCI: Using configuration type 1 for base access
<7>ACPI: EC: Look up EC in DSDT
<6>ACPI: Interpreter enabled
<6>ACPI: (supports S0 S1 S5)
<6>ACPI: Using IOAPIC for interrupt routing
<6>ACPI: No dock devices found.
<6>ACPI: PCI Root Bridge [PCI0] (0000:00)
<7>pci 0000:00:01.1: reg 10 io port: [0xe800-0xe83f]
[....]

Re: ACPI exception with 2.6.29-rc6

[Robert Hancock]

Heinz Diehl wrote:
> Hi,
> 
> booting 2.6.29-rc6 shows the following in boot.log:
> 
> [....]
> <7>bus: 00 index 4 mmio: [230000000, fcffffffff]
> <6>ACPI: bus type pci registered
> <5>PCI: MCFG configuration 0: base f0000000 segment 0 buses 0 - 127
> <5>PCI: MCFG area at f0000000 reserved in E820
> <6>PCI: Using MMCONFIG at f0000000 - f7ffffff
> <6>PCI: Using configuration type 1 for base access
> <4>bio: create slab <bio-0> at 0
> <7>ACPI: EC: Look up EC in DSDT
> --> <3>ACPI: Denied BIOS AML access to invalid port 0x4d0+0x2 (ELCR)
> --> <4>ACPI Exception (dsopcode-0419): AE_AML_ILLEGAL_ADDRESS, During address validation of OpRegion [ELCR] [20081204]

Your BIOS defines an operation region on some IO addresses that the 
kernel will not allow it to access since they are things that BIOS AML 
code is not supposed to be poking with. This check was recently added. 
Windows XP and later also disallow AML access to these registers.

Note that this doesn't necessarily mean that the BIOS is actually trying 
to access those registers. On my A8N-SLI Deluxe machine, the ACPI AML 
defines an operation region for the ELCR register, but it doesn't seem 
like it is ever used.

In any case.. nothing to really worry about.