intel_idle: Disable Baytrail Core and Module C6 auto-demotion

Power efficiency improves on Baytrail (Intel Atom Processor E3000)
when Linux disables C6 auto-demotion.

Based on work by Srinidhi Kasagar <srinidhi.kasagar@intel.com>.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
This commit is contained in:
Len Brown
2014-07-31 15:21:24 -04:00
parent 19583ca584
commit 8c058d53f6
2 changed files with 10 additions and 0 deletions

View File

@@ -89,6 +89,7 @@ struct idle_cpu {
* Indicate which enable bits to clear here.
*/
unsigned long auto_demotion_disable_flags;
bool byt_auto_demotion_disable_flag;
bool disable_promotion_to_c1e;
};
@@ -613,6 +614,7 @@ static const struct idle_cpu idle_cpu_snb = {
static const struct idle_cpu idle_cpu_byt = {
.state_table = byt_cstates,
.disable_promotion_to_c1e = true,
.byt_auto_demotion_disable_flag = true,
};
static const struct idle_cpu idle_cpu_ivb = {
@@ -814,6 +816,11 @@ static int __init intel_idle_cpuidle_driver_init(void)
if (icpu->auto_demotion_disable_flags)
on_each_cpu(auto_demotion_disable, NULL, 1);
if (icpu->byt_auto_demotion_disable_flag) {
wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
}
if (icpu->disable_promotion_to_c1e) /* each-cpu is redundant */
on_each_cpu(c1e_promotion_disable, NULL, 1);