[Intel-gfx] [PATCH 1/2] drm/i915: Runtime disable for eDP DRRS

[Ramalingam C]

From: "C, Ramalingam" <ramalingam.c at intel.com>

Module parameter enable_drrs(Boolean flag) is added to control the
eDP Idleness drrs enable flow.

Modification to this module parameter will be considered on next
eDP_DRRS enable flow. So after module parameter update, a modeset
will help to modify the feature state as per the module parameter's
current state.

Possibility of disabling the DRRS, enables the testing of the
frontbuffer tracking based features (FBC, DRRS and PSR) as standalone
or any combination of the set.

Signed-off-by: C, Ramalingam <ramalingam.c at intel.com>
---
 drivers/gpu/drm/i915/i915_params.c | 3 +++
 drivers/gpu/drm/i915/i915_params.h | 3 ++-
 drivers/gpu/drm/i915/intel_dp.c    | 6 ++++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index b4faeb6aa2bd..32f06bb74f9d 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -190,3 +190,6 @@ i915_param_named(enable_dpcd_backlight, bool, 0600,
 
 i915_param_named(enable_gvt, bool, 0400,
 	"Enable support for Intel GVT-g graphics virtualization host support(default:false)");
+
+i915_param_named_unsafe(enable_drrs, bool, 0600,
+	"Enable DRRS. (True=Enabled, False=Disabled [Default])");
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index c7292268ed43..3c6fdce1c122 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -67,7 +67,8 @@
 	param(bool, nuclear_pageflip, false) \
 	param(bool, enable_dp_mst, true) \
 	param(bool, enable_dpcd_backlight, false) \
-	param(bool, enable_gvt, false)
+	param(bool, enable_gvt, false) \
+	param(bool, enable_drrs, false)
 
 #define MEMBER(T, member, ...) T member;
 struct i915_params {
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ca48bce23a6f..ff9964cf15cd 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5568,6 +5568,11 @@ void intel_edp_drrs_enable(struct intel_dp *intel_dp,
 		return;
 	}
 
+	if (!i915_modparams.enable_drrs) {
+		DRM_DEBUG_KMS("DRRS is disabled from modparams\n");
+		return;
+	}
+
 	mutex_lock(&dev_priv->drrs.mutex);
 	if (WARN_ON(dev_priv->drrs.dp)) {
 		DRM_ERROR("DRRS already enabled\n");
@@ -5817,6 +5822,7 @@ intel_dp_drrs_init(struct intel_connector *intel_connector,
 	}
 
 	dev_priv->drrs.type = dev_priv->vbt.drrs_type;
+	i915_modparams.enable_drrs = true;
 
 	dev_priv->drrs.refresh_rate_type = DRRS_HIGH_RR;
 	DRM_DEBUG_KMS("seamless DRRS supported for eDP panel.\n");
-- 
2.7.4