diff options
| -rw-r--r-- | drivers/acpi/processor_idle.c | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 0cad56ca342b..943a88069001 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1514,23 +1514,38 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, } else { acpi_idle_update_bm_rld(pr, cx); - spin_lock(&c3_lock); - c3_cpu_count++; - /* Disable bus master arbitration when all CPUs are in C3 */ - if (c3_cpu_count == num_online_cpus()) - acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1); - spin_unlock(&c3_lock); + /* + * disable bus master + * bm_check implies we need ARB_DIS + * !bm_check implies we need cache flush + * bm_control implies whether we can do ARB_DIS + * + * That leaves a case where bm_check is set and bm_control is + * not set. In that case we cannot do much, we enter C3 + * without doing anything. + */ + if (pr->flags.bm_check && pr->flags.bm_control) { + spin_lock(&c3_lock); + c3_cpu_count++; + /* Disable bus master arbitration when all CPUs are in C3 */ + if (c3_cpu_count == num_online_cpus()) + acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1); + spin_unlock(&c3_lock); + } else if (!pr->flags.bm_check) { + ACPI_FLUSH_CPU_CACHE(); + } t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); acpi_idle_do_entry(cx); t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); - spin_lock(&c3_lock); /* Re-enable bus master arbitration */ - if (c3_cpu_count == num_online_cpus()) + if (pr->flags.bm_check && pr->flags.bm_control) { + spin_lock(&c3_lock); acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0); - c3_cpu_count--; - spin_unlock(&c3_lock); + c3_cpu_count--; + spin_unlock(&c3_lock); + } } #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC) |