Author: jkim
Date: Fri Mar 4 22:59:14 2011
New Revision: 219277
URL: http://svn.freebsd.org/changeset/base/219277
Log:
MFC: r219046
Set C1 "I/O then Halt" capability bit for Intel EIST. Some broken BIOSes
refuse to load external SSDTs if this bit is unset for _PDC.
Modified:
stable/8/sys/x86/cpufreq/est.c
Directory Properties:
stable/8/sys/ (props changed)
stable/8/sys/amd64/include/xen/ (props changed)
stable/8/sys/cddl/contrib/opensolaris/ (props changed)
stable/8/sys/contrib/dev/acpica/ (props changed)
stable/8/sys/contrib/pf/ (props changed)
Modified: stable/8/sys/x86/cpufreq/est.c
==============================================================================
--- stable/8/sys/x86/cpufreq/est.c Fri Mar 4 22:26:41 2011 (r219276)
+++ stable/8/sys/x86/cpufreq/est.c Fri Mar 4 22:59:14 2011 (r219277)
@@ -945,8 +945,11 @@ static int
est_features(driver_t *driver, u_int *features)
{
- /* Notify the ACPI CPU that we support direct access to MSRs */
- *features = ACPI_CAP_PERF_MSRS;
+ /*
+ * Notify the ACPI CPU that we support direct access to MSRs.
+ * XXX C1 "I/O then Halt" seems necessary for some broken BIOS.
+ */
+ *features = ACPI_CAP_PERF_MSRS | ACPI_CAP_C1_IO_HALT;
return (0);
}