Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e17bcb...
Commit: e17bcb43a26a7111f851b5ff6d1258ecd355de75
Parent: 167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri Dec 7 19:16:17 2007 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri Dec 7 19:16:17 2007 +0100
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
---
drivers/acpi/processor_idle.c | 19 ++++++++++++++-----
1 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index b1fbee3..2fe34cc 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -531,6 +531,11 @@ static void acpi_processor_idle(void)
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
* !bm_check implies we need cache flush
@@ -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);
-
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