drm/i915: Fix broken mst get_hw_state.

connector->encoder is initialized as NULL. Fix this by setting it in
during pre enable. MST connectors are not read out during initial hw
readout, and have no fixed encoder mappings. So it's harmless to
return false when the connector has never been assigned to an encoder.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ca9278be49f7..8cc9264f7809 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6305,7 +6305,7 @@ static void intel_connector_check_state(struct intel_connector *connector)
                       connector->base.name);
 
         if (connector->get_hw_state(connector)) {
-                struct drm_encoder *encoder = &connector->encoder->base;
+                struct intel_encoder *encoder = connector->encoder;
                 struct drm_connector_state *conn_state = connector->base.state;
 
                 I915_STATE_WARN(!crtc,
@@ -6317,13 +6317,13 @@ static void intel_connector_check_state(struct intel_connector *connector)
                 I915_STATE_WARN(!crtc->state->active,
                       "connector is active, but attached crtc isn't\n");
 
-                if (!encoder)
+                if (!encoder || encoder->type == INTEL_OUTPUT_DP_MST)
                         return;
 
-                I915_STATE_WARN(conn_state->best_encoder != encoder,
+                I915_STATE_WARN(conn_state->best_encoder != &encoder->base,
                         "atomic encoder doesn't match attached encoder\n");
 
-                I915_STATE_WARN(conn_state->crtc != encoder->crtc,
+                I915_STATE_WARN(conn_state->crtc != encoder->base.crtc,
                         "attached encoder crtc differs from connector crtc\n");
         } else {
                 I915_STATE_WARN(crtc && crtc->state->active,