On Friday, December 20, 2013 01:10:26 PM H. Peter Anvin wrote: > On 12/19/2013 09:38 PM, joeyli wrote: > > > > If don't use EFI time, then the first priority is using ACPI TAD if it > > present. Due to ACPI TAD is a generic acpi device that's need OS parsing > > DSDT table before set system time. > > > > Either move DSDT parser from subsystem initial stage to start_kernel or > > move timekeeping initial to after DSDT be parsed. Which one you think is > > more possible and risk less? Then I will try that way. > > > > I discussed the DSDT/SSDT parsing issue with Rafael and he claims it > would require a lot of restructuring. Unfortunately ACPI is at this > point done rather late, as I understand. All of this is a big problem. My understanding, however, is that to use the TAD, we don't actually need to create a struct acpi_device for it. We just need a handle to the ACPICA object which can be found using acpi_get_devices() as soon as the namespace has been extracted from the DSDT and friends. That in turn happens in acpi_early_init(), which is called from start_kernel() right before efi_late_init(). Is that early enough? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
