[Intel-gfx] [PATCH v2 11/12] drm/i915/gen9: Add boot parameter for disabling DC6

[Patrik Jakobsson]

v2: Use _unsafe (Jani)

Signed-off-by: Patrik Jakobsson <patrik.jakobsson at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h         | 1 +
 drivers/gpu/drm/i915/i915_params.c      | 6 ++++++
 drivers/gpu/drm/i915/intel_runtime_pm.c | 4 ++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c0252ef..5628c5a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2639,6 +2639,7 @@ struct i915_params {
 	int panel_use_ssc;
 	int vbt_sdvo_panel_type;
 	int enable_rc6;
+	int enable_dc6;
 	int enable_fbc;
 	int enable_ppgtt;
 	int enable_execlists;
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 368df67..6457f3a 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -32,6 +32,7 @@ struct i915_params i915 __read_mostly = {
 	.panel_use_ssc = -1,
 	.vbt_sdvo_panel_type = -1,
 	.enable_rc6 = -1,
+	.enable_dc6 = 1,
 	.enable_fbc = -1,
 	.enable_execlists = -1,
 	.enable_hangcheck = true,
@@ -79,6 +80,11 @@ MODULE_PARM_DESC(enable_rc6,
 	"For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. "
 	"default: -1 (use per-chip default)");
 
+module_param_named_unsafe(enable_dc6, i915.enable_dc6, int, 0400);
+MODULE_PARM_DESC(enable_dc6,
+	"Enable power-saving display C-state 6. "
+	"(0 = disable; 1 = enable [default])");
+
 module_param_named_unsafe(enable_fbc, i915.enable_fbc, int, 0600);
 MODULE_PARM_DESC(enable_fbc,
 	"Enable frame buffer compression for power savings "
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 95c3fcc..62c1273 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -708,7 +708,7 @@ static void gen9_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
 static void gen9_dc_off_power_well_disable(struct drm_i915_private *dev_priv,
 					  struct i915_power_well *power_well)
 {
-	if (IS_SKYLAKE(dev_priv))
+	if (IS_SKYLAKE(dev_priv) && i915.enable_dc6)
 		skl_enable_dc6(dev_priv);
 	else
 		gen9_enable_dc5(dev_priv);
@@ -720,7 +720,7 @@ static void gen9_dc_off_power_well_sync_hw(struct drm_i915_private *dev_priv,
 	if (power_well->count > 0) {
 		gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
 	} else {
-		if (IS_SKYLAKE(dev_priv))
+		if (IS_SKYLAKE(dev_priv) && i915.enable_dc6)
 			gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC6);
 		else
 			gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC5);
-- 
2.5.0