From c1c306344669ca40255e36192b101060ffbb1271 Mon Sep 17 00:00:00 2001 From: Alexey Starikovskiy Date: Mon, 26 Nov 2007 20:42:19 +0100 Subject: [PATCH] ACPI: Set max_cstate to 1 for early Opterons. AMD Opteron processors before CG revision don't like C-states > 1. This solves the long standing bugzilla #5303 and probably some more on affected machines: http://bugzilla.kernel.org/show_bug.cgi?id=5303 [ tglx@linutronix.de: reworked the patch so it does not wreck ia64 ] Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- drivers/acpi/processor_idle.c | 1 + include/asm-ia64/acpi.h | 1 + include/asm-x86/acpi.h | 27 +++++++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index f996d0e37689..b52109bd06d2 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1658,6 +1658,7 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, if (!first_run) { dmi_check_system(processor_power_dmi_table); + max_cstate = acpi_processor_cstate_check(max_cstate); if (max_cstate < ACPI_C_STATES_MAX) printk(KERN_NOTICE "ACPI: processor limited to max C-state %d\n", diff --git a/include/asm-ia64/acpi.h b/include/asm-ia64/acpi.h index 49730ffbbae4..81bcd5e51789 100644 --- a/include/asm-ia64/acpi.h +++ b/include/asm-ia64/acpi.h @@ -94,6 +94,7 @@ ia64_acpi_release_global_lock (unsigned int *lock) #define acpi_noirq 0 /* ACPI always enabled on IA64 */ #define acpi_pci_disabled 0 /* ACPI PCI always enabled on IA64 */ #define acpi_strict 1 /* no ACPI spec workarounds on IA64 */ +#define acpi_processor_cstate_check(x) (x) /* no idle limits on IA64 :) */ static inline void disable_acpi(void) { } const char *acpi_get_sysname (void); diff --git a/include/asm-x86/acpi.h b/include/asm-x86/acpi.h index 0693689d4146..f8a89793ac8c 100644 --- a/include/asm-x86/acpi.h +++ b/include/asm-x86/acpi.h @@ -1,5 +1,32 @@ +#ifndef _ASM_X86_ACPI_H +#define _ASM_X86_ACPI_H + #ifdef CONFIG_X86_32 # include "acpi_32.h" #else # include "acpi_64.h" #endif + +#include + +/* + * Check if the CPU can handle C2 and deeper + */ +static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate) +{ + /* + * Early models (<=5) of AMD Opterons are not supposed to go into + * C2 state. + * + * Steppings 0x0A and later are good + */ + if (boot_cpu_data.x86 == 0x0F && + boot_cpu_data.x86_vendor == X86_VENDOR_AMD && + boot_cpu_data.x86_model <= 0x05 && + boot_cpu_data.x86_mask < 0x0A) + return 1; + else + return max_cstate; +} + +#endif