On Wed, Jan 06, 2010 at 03:22:30PM -0500, Len Brown wrote: > I've looked at _OSI use in over a hundred DSDTs and never > seen run-time re-configuration of reset support. The point isn't that the firmware changes its behaviour - the point is that the OS does. > I do not think the BIOS has a run-time decision to make here. > If a box is designed to support Windows XP and newer, it is > likely that ACPI_RESET is simply valid and XP blindly uses it. > If reset fails, the box doesn't pass WHQL and the box is fixed. > If W2K is run on that box, ACPI_RESET is still valid, just that > W2K chooses to not write to it. And if ACPI_RESET is set but untested (because 2000 never used it)? > We can't rely on blind use of _OSI to mean "new enough", since > it was supported back in W2K era. That means we have to parse > the OSI strings. But what happens when a BIOS writer decides to > evaluate _OSI("Windows Future") without evaluating any of the > old strings we know about? We would disable ACPI reset on such > a future box? Potentially, yes. But since such a machine would clearly expect to be treated as "Windows Future", we'd be running it in an untested configuration anyway. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx -- 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