From: Venkatesh Pallipadi Date: Tue, 20 Nov 2007 02:43:22 +0000 (-0500) Subject: cpuidle: fix HP nx6125 regression X-Git-Tag: v2.6.24-rc4~107^2~6^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ddc081a19585c8ba5aad437779950c2ef215360a;p=linux-2.6 cpuidle: fix HP nx6125 regression Fix for http://bugzilla.kernel.org/show_bug.cgi?id=9355 cpuidle always used to fallback to C2 if there is some bm activity while entering C3. But, presence of C2 is not always guaranteed. Change cpuidle algorithm to detect a safe_state to fallback in case of bm_activity and use that state instead of C2. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 1af0694e85..8904f5c82a 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -197,6 +197,19 @@ static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2) return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2); } +static void acpi_safe_halt(void) +{ + current_thread_info()->status &= ~TS_POLLING; + /* + * TS_POLLING-cleared state must be visible before we + * test NEED_RESCHED: + */ + smp_mb(); + if (!need_resched()) + safe_halt(); + current_thread_info()->status |= TS_POLLING; +} + #ifndef CONFIG_CPU_IDLE static void @@ -239,19 +252,6 @@ acpi_processor_power_activate(struct acpi_processor *pr, return; } -static void acpi_safe_halt(void) -{ - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); - if (!need_resched()) - safe_halt(); - current_thread_info()->status |= TS_POLLING; -} - static atomic_t c3_cpu_count; /* Common C-state entry for C2, C3, .. */ @@ -1385,15 +1385,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, if (pr->flags.bm_check) acpi_idle_update_bm_rld(pr, cx); - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we test - * NEED_RESCHED: - */ - smp_mb(); - if (!need_resched()) - safe_halt(); - current_thread_info()->status |= TS_POLLING; + acpi_safe_halt(); cx->usage++; @@ -1493,6 +1485,15 @@ 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 (dev->safe_state) { + return dev->safe_state->enter(dev, dev->safe_state); + } else { + acpi_safe_halt(); + return 0; + } + } + local_irq_disable(); current_thread_info()->status &= ~TS_POLLING; /* @@ -1515,49 +1516,39 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, */ acpi_state_timer_broadcast(pr, cx, 1); - if (acpi_idle_bm_check()) { - cx = pr->power.bm_state; - - acpi_idle_update_bm_rld(pr, cx); - - t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); - acpi_idle_do_entry(cx); - t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); - } else { - acpi_idle_update_bm_rld(pr, cx); + acpi_idle_update_bm_rld(pr, cx); - /* - * 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(); - } + /* + * 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); + t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); + acpi_idle_do_entry(cx); + t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); - /* Re-enable bus master arbitration */ - 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); - } + /* Re-enable bus master arbitration */ + 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); } #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC) @@ -1626,12 +1617,14 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) case ACPI_STATE_C1: state->flags |= CPUIDLE_FLAG_SHALLOW; state->enter = acpi_idle_enter_c1; + dev->safe_state = state; break; case ACPI_STATE_C2: state->flags |= CPUIDLE_FLAG_BALANCED; state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_simple; + dev->safe_state = state; break; case ACPI_STATE_C3: @@ -1652,14 +1645,6 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) if (!count) return -EINVAL; - /* find the deepest state that can handle active BM */ - if (pr->flags.bm_check) { - for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) - if (pr->power.states[i].type == ACPI_STATE_C3) - break; - pr->power.bm_state = &pr->power.states[i-1]; - } - return 0; } diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 26d79f6db8..76411b1fc4 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -78,7 +78,6 @@ struct acpi_processor_cx { struct acpi_processor_power { struct cpuidle_device dev; struct acpi_processor_cx *state; - struct acpi_processor_cx *bm_state; unsigned long bm_check_timestamp; u32 default_state; u32 bm_activity; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 16a51546db..c4e00161a2 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -92,6 +92,7 @@ struct cpuidle_device { struct kobject kobj; struct completion kobj_unregister; void *governor_data; + struct cpuidle_state *safe_state; }; DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);