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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2007-11-19 19:48:00 -0500
committerLen Brown <len.brown@intel.com>2007-11-19 21:25:23 -0500
commitc9c860e5349ef62cd9226694b3aa625ef66f504e (patch)
tree19ce87dd625256a6a3c73b6eac147b3818d93b18 /drivers/acpi/processor_idle.c
parent83788c0caed3a425f64fa88fde7c78746b9cdd76 (diff)
cpuidle: fix C3 for no bus-master control case
Port 18eab8550397f1f3d4b8b2c5257c88dae25d58ed (Enable C3 even when PM2_control is zero) to cpuidle. Without this patch, some systems will notice a regression when enabling CPU_IDLE -- C3 would no longer be available. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c35
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)