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cpuidle: fix C3 for no bus-master control case 

Port 18eab85503
(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>
This commit is contained in:
Venkatesh Pallipadi 2007-11-19 19:48:00 -05:00 committed by Len Brown
parent 83788c0cae
commit c9c860e534
1 changed files with 25 additions and 10 deletions
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35
drivers/acpi/processor_idle.c
View File

@ -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)