[Intel-gfx] [PATCH] drm/i915/gt: Select the deepest available parking mode for rc6

[Chris Wilson]

On Ivybridge, we can go lower than rc6 to rc6p. And this is required for
Ivybridge to hit the same minimum power consumption as rc6 on other
platforms, so make it so.

Fixes: 730eaeb52426 ("drm/i915/gt: Manual rc6 entry upon parking")
Testcase: igt/i915_pm_rc6_residency/rc6-idle
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Cc: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_rc6.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c
index 50aa63270cdc..09d3e5a45397 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6.c
+++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
@@ -608,6 +608,7 @@ void intel_rc6_unpark(struct intel_rc6 *rc6)
 void intel_rc6_park(struct intel_rc6 *rc6)
 {
 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
+	unsigned int target;
 
 	if (!rc6->enabled)
 		return;
@@ -622,7 +623,14 @@ void intel_rc6_park(struct intel_rc6 *rc6)
 
 	/* Turn off the HW timers and go directly to rc6 */
 	set(uncore, GEN6_RC_CONTROL, GEN6_RC_CTL_RC6_ENABLE);
-	set(uncore, GEN6_RC_STATE, 0x4 << RC_SW_TARGET_STATE_SHIFT);
+
+	if (HAS_RC6pp(rc6_to_i915(rc6)))
+		target = 0x6; /* deepest rc6 */
+	else if (HAS_RC6p(rc6_to_i915(rc6)))
+		target = 0x5; /* deep rc6 */
+	else
+		target = 0x4; /* normal rc6 */
+	set(uncore, GEN6_RC_STATE, target << RC_SW_TARGET_STATE_SHIFT);
 }
 
 void intel_rc6_disable(struct intel_rc6 *rc6)
-- 
2.20.1