From e17bcb43a26a7111f851b5ff6d1258ecd355de75 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Dec 2007 19:16:17 +0100 Subject: [PATCH] ACPI: move timer broadcast before busmaster disable The timer broadcast code might access HPET, which should not be accessed after the busmaster disable. In acpi_idle_enter_simple() this change also prevents, that we modify the busmaster state without going actually idle. This might leave the ACPI bm state in a stale state, when we leave the function early in the need_resched() check. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Acked-by: Venkatesh Pallipadi --- drivers/acpi/processor_idle.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index b1fbee3f7fe1..2fe34cc73c13 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -530,6 +530,11 @@ static void acpi_processor_idle(void) break; case ACPI_STATE_C3: + /* + * Must be done before busmaster disable as we might + * need to access HPET ! + */ + acpi_state_timer_broadcast(pr, cx, 1); /* * disable bus master * bm_check implies we need ARB_DIS @@ -557,7 +562,6 @@ static void acpi_processor_idle(void) /* Get start time (ticks) */ t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); /* Invoke C3 */ - acpi_state_timer_broadcast(pr, cx, 1); /* Tell the scheduler that we are going deep-idle: */ sched_clock_idle_sleep_event(); acpi_cstate_enter(cx); @@ -1401,9 +1405,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, if (acpi_idle_suspend) return(acpi_idle_enter_c1(dev, state)); - if (pr->flags.bm_check) - acpi_idle_update_bm_rld(pr, cx); - local_irq_disable(); current_thread_info()->status &= ~TS_POLLING; /* @@ -1418,13 +1419,21 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, return 0; } + /* + * Must be done before busmaster disable as we might need to + * access HPET ! + */ + acpi_state_timer_broadcast(pr, cx, 1); + + if (pr->flags.bm_check) + acpi_idle_update_bm_rld(pr, cx); + if (cx->type == ACPI_STATE_C3) ACPI_FLUSH_CPU_CACHE(); t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); /* Tell the scheduler that we are going deep-idle: */ sched_clock_idle_sleep_event(); - acpi_state_timer_broadcast(pr, cx, 1); acpi_idle_do_entry(cx); t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); -- 2.20.1