On Thu, Jul 06, 2006 at 11:46:04PM -0300, Henrique de Moraes Holschuh wrote: > On Thu, 06 Jul 2006, Vojtech Pavlik wrote: > > > >We are investigating the ACPI global lock as a way to at least get the > > > >SMBIOS to stay away from the EC while we talk to it, but we don't know if > > > >the entire SMBIOS firmware respects that lock. > > > > > > It had better, that is exactly what the ACPI Global Lock is supposed to > > > prevent (concurrent access to non-sharable resources between the OS and > > > SMI code). The ACPI DSDT contains information on whether or not the > > > machine requires the Global Lock in order to access the EC or whether it > > > is safe to access without locking. > > > > Isn't that vaild only if you actully use ACPI to access the EC? (AFAIK > > the HDAPS driver does direct port access.) > > It better be valid for any OS-side access to the EC, otherwise the ACPI > global lock would be utterly useless. The system vendor would have done its > own "global-lock-like" functionality without the need for an ACPI global > lock specification. That's what I fear does happen on many systems. > What is not clear to me is whether an ACPI DSDT method is on the "OS side" > or on the "SMM side" of the ACPI global lock. No idea, sorry. -- Vojtech Pavlik Director SuSE Labs
