diff options
| -rw-r--r-- | arch/x86/kernel/acpi/cstate.c | 9 | ||||
| -rw-r--r-- | drivers/acpi/processor_idle.c | 7 | ||||
| -rw-r--r-- | include/acpi/processor.h | 3 |
3 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index 2e837f5080f..fb7a5f052e2 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -145,6 +145,15 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, percpu_entry->states[cx->index].eax = cx->address; percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK; } + + /* + * For _CST FFH on Intel, if GAS.access_size bit 1 is cleared, + * then we should skip checking BM_STS for this C-state. + * ref: "Intel Processor Vendor-Specific ACPI Interface Specification" + */ + if ((c->x86_vendor == X86_VENDOR_INTEL) && !(reg->access_size & 0x2)) + cx->bm_sts_skip = 1; + return retval; } EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe); diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index b1b385692f4..1d410485529 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -76,6 +76,8 @@ static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; module_param(max_cstate, uint, 0000); static unsigned int nocst __read_mostly; module_param(nocst, uint, 0000); +static int bm_check_disable __read_mostly; +module_param(bm_check_disable, uint, 0000); static unsigned int latency_factor __read_mostly = 2; module_param(latency_factor, uint, 0644); @@ -763,6 +765,9 @@ static int acpi_idle_bm_check(void) { u32 bm_status = 0; + if (bm_check_disable) + return 0; + acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); if (bm_status) acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); @@ -947,7 +952,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, if (acpi_idle_suspend) return(acpi_idle_enter_c1(dev, state)); - if (acpi_idle_bm_check()) { + if (!cx->bm_sts_skip && acpi_idle_bm_check()) { if (dev->safe_state) { dev->last_state = dev->safe_state; return dev->safe_state->enter(dev, dev->safe_state); diff --git a/include/acpi/processor.h b/include/acpi/processor.h index da565a48240..a68ca8a11a5 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -48,7 +48,7 @@ struct acpi_power_register { u8 space_id; u8 bit_width; u8 bit_offset; - u8 reserved; + u8 access_size; u64 address; } __attribute__ ((packed)); @@ -63,6 +63,7 @@ struct acpi_processor_cx { u32 power; u32 usage; u64 time; + u8 bm_sts_skip; char desc[ACPI_CX_DESC_LEN]; }; |