Trust the ACPI code to disable TSC instead when C3 is used.
AMD Fam10h does not disable TSC in any C states so the
check was incorrect there anyways after the change
to handle this like Intel on AMD too.
This allows to use the TSC when C3 is disabled in software
(acpi.max_c_state=2), but the BIOS supports it anyways.
Match i386 behaviour.
Cc: [EMAIL PROTECTED]
Signed-off-by: Andi Kleen <[EMAIL PROTECTED]>
---
arch/x86/kernel/tsc_64.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
Index: linux/arch/x86/kernel/tsc_64.c
===================================================================
--- linux.orig/arch/x86/kernel/tsc_64.c
+++ linux/arch/x86/kernel/tsc_64.c
@@ -277,15 +277,8 @@ __cpuinit int unsynchronized_tsc(void)
return 1;
#endif
- if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
-#ifdef CONFIG_ACPI
- /* But TSC doesn't tick in C3 so don't use it there */
- if (acpi_gbl_FADT.header.length > 0 &&
- acpi_gbl_FADT.C3latency < 1000)
- return 1;
-#endif
+ if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
return 0;
- }
/* Assume multi socket systems are not synchronized */
return num_present_cpus() > 1;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
