drm/i915/dp_mst: Fix connector initialization in intel_dp_add_mst_connector()

The connector initialization in intel_dp_add_mst_connector() depends on
the device pointer in connector to be valid, at least by connector
debug printing. The device pointer is initialized by drm_connector_init(),
however that function also exposes the connector to in-kernel users,
which can't be done before the connector is fully initialized. For now
make sure the device pointer is valid before it's used, until a
follow-up change moving this to DRM core.

This issue was revealed by the commit in the Fixes: line below, before
which the above debug printing checked and handled a NULL device pointer
gracefully in DRM core.

Cc: Jani Nikula <jani.nikula@intel.com>
Fixes: 529798bd786a ("drm/i915/mst: convert to struct intel_display")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12799
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241118131044.1278028-1-imre.deak@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index df7edcfe885b6c0495585e0a29c33652a33ddb23..f058360a264137e08897bea08f35ef5504d7b650 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1727,6 +1727,16 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 
        intel_dp_init_modeset_retry_work(intel_connector);
 
+       /*
+        * TODO: The following drm_connector specific initialization belongs
+        * to DRM core, however it happens atm too late in
+        * drm_connector_init(). That function will also expose the connector
+        * to in-kernel users, so it can't be called until the connector is
+        * sufficiently initialized; init the device pointer used by the
+        * following DSC setup, until a fix moving this to DRM core.
+        */
+       intel_connector->base.dev = mgr->dev;
+
        intel_connector->dp.dsc_decompression_aux = drm_dp_mst_dsc_aux_for_port(port);
        intel_dp_mst_read_decompression_port_dsc_caps(intel_dp, intel_connector);
        intel_connector->dp.dsc_hblank_expansion_quirk =