• Ville Syrjälä's avatar
    drm/i915: Do not create a new max_bpc prop for MST connectors · ed5fa906
    Ville Syrjälä authored
    We're not allowed to create new properties after device registration
    so for MST connectors we need to either create the max_bpc property
    earlier, or we reuse one we already have. Let's do the latter apporach
    since the corresponding SST connector already has the prop and its
    min/max are correct also for the MST connector.
    The problem was highlighted by commit 4f5368b5541a ("drm/kms:
    Catch mode_object lifetime errors") which results in the following
    [ 1330.878941] WARNING: CPU: 2 PID: 1554 at drivers/gpu/drm/drm_mode_object.c:45 __drm_mode_object_add+0xa0/0xb0 [drm]
    [ 1330.879008] Call Trace:
    [ 1330.879023]  drm_property_create+0xba/0x180 [drm]
    [ 1330.879036]  drm_property_create_range+0x15/0x30 [drm]
    [ 1330.879048]  drm_connector_attach_max_bpc_property+0x62/0x80 [drm]
    [ 1330.879086]  intel_dp_add_mst_connector+0x11f/0x140 [i915]
    [ 1330.879094]  drm_dp_add_port.isra.20+0x20b/0x440 [drm_kms_helper]
    Cc: stable@vger.kernel.org
    Cc: Lyude Paul <lyude@redhat.com>
    Cc: sunpeng.li@amd.com
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Cc: Sean Paul <sean@poorly.run>
    Fixes: 5ca0ef8a
     ("drm/i915: Add max_bpc property for DP MST")
    Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20190820161657.9658-1-ville.syrjala@linux.intel.com
    Reviewed-by: default avatarJosé Roberto de Souza <jose.souza@intel.com>
    Reviewed-by: default avatarLyude Paul <lyude@redhat.com>
    (cherry picked from commit 1b9bd09630d4db4827cc04d358a41a16a6bc2cb0)
    Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
intel_dp_mst.c 21 KB