On Friday, 24 of October 2008, James Bottomley wrote: > On Thu, 2008-10-23 at 22:42 +0200, Rafael J. Wysocki wrote: > > On Thursday, 23 of October 2008, James Bottomley wrote: > > > ACPI Warning (nseval-0168): Insufficient arguments - method [_OSC] needs 5, found 4 [20080926] > > > ACPI Warning (nspredef-0252): \_SB_.PCI0._OSC: Parameter count mismatch - ASL declared 5, expected 4 [20080926] > > > ACPI Error (nspredef-0163): \_SB_.PCI0._OSC: Missing expected return value [20080926] > > > BUG: unable to handle kernel NULL pointer dereference at 00000000 > > Does this patch help? > > > > --- > > drivers/pci/pci-acpi.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > Index: linux-2.6/drivers/pci/pci-acpi.c > > =================================================================== > > --- linux-2.6.orig/drivers/pci/pci-acpi.c > > +++ linux-2.6/drivers/pci/pci-acpi.c > > @@ -83,6 +83,9 @@ static acpi_status acpi_run_osc(acpi_han > > if (ACPI_FAILURE(status)) > > return status; > > > > + if (!output.pointer) > > + return AE_NULL_OBJECT; > > + > > out_obj = output.pointer; > > if (out_obj->type != ACPI_TYPE_BUFFER) { > > printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n"); > > Yes, that seems to fix it, thanks! ... I suppose the ASL error and > warnings need investigating too? Unfortunately, they seem to indicate a BIOS breakage. According to the spec, _OSC should take 4 arguments, but apparently on your system it wants 5. The output of acpidump may be helpful, as Lin Ming already said. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html