[Intel-gfx] [PATCH] drm/i915: Set crtc->new_config to NULL for pipes that are about to be disabled

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

crtc->new_config is only relevant for pipes that are going to be active
post-modeset. Set the pointer to NULL for all pipes that are going to
be disabled. This is done to help catch bugs where some piece of code
would go looking at crtc->new_config even if the data there is stale.

Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 673b02e..5b5b46e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8763,6 +8763,11 @@ static void intel_modeset_update_staged_output_state(struct drm_device *dev)
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list,
 			    base.head) {
 		crtc->new_enabled = crtc->base.enabled;
+
+		if (crtc->new_enabled)
+			crtc->new_config = &crtc->config;
+		else
+			crtc->new_config = NULL;
 	}
 }
 
@@ -9195,7 +9200,9 @@ intel_modeset_update_state(struct drm_device *dev, unsigned prepare_pipes)
 	list_for_each_entry(intel_crtc, &dev->mode_config.crtc_list,
 			    base.head) {
 		WARN_ON(intel_crtc->base.enabled != intel_crtc_in_use(&intel_crtc->base));
-		WARN_ON(intel_crtc->new_config != &intel_crtc->config);
+		WARN_ON(intel_crtc->new_config &&
+			intel_crtc->new_config != &intel_crtc->config);
+		WARN_ON(intel_crtc->base.enabled != !!intel_crtc->new_config);
 	}
 
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
@@ -9801,6 +9808,11 @@ static void intel_set_config_restore_state(struct drm_device *dev,
 	count = 0;
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, base.head) {
 		crtc->new_enabled = config->save_crtc_enabled[count++];
+
+		if (crtc->new_enabled)
+			crtc->new_config = &crtc->config;
+		else
+			crtc->new_config = NULL;
 	}
 
 	count = 0;
@@ -10002,6 +10014,11 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 				      crtc->new_enabled ? "en" : "dis");
 			config->mode_changed = true;
 		}
+
+		if (crtc->new_enabled)
+			crtc->new_config = &crtc->config;
+		else
+			crtc->new_config = NULL;
 	}
 
 	return 0;
@@ -10272,8 +10289,6 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 	dev_priv->plane_to_crtc_mapping[intel_crtc->plane] = &intel_crtc->base;
 	dev_priv->pipe_to_crtc_mapping[intel_crtc->pipe] = &intel_crtc->base;
 
-	intel_crtc->new_config = &intel_crtc->config;
-
 	drm_crtc_helper_add(&intel_crtc->base, &intel_helper_funcs);
 }
 
-- 
1.8.3.2