From: hersen wu <hersenxs.wu@xxxxxxx> commit b448d30b0c303d5454ea572b772d1ffae96bc6e7 upstream. [Why] amdgpu_dm->backlight_caps is for single eDP only. the caps are upddated for very connector. Real eDP caps will be overwritten by other external display. For OLED panel, caps->aux_support is set to 1 for OLED pnael. after external connected, caps+.aux_support is set to 0. This causes OLED backlight adjustment not work. [How] within update_conector_ext_caps, backlight caps will be updated only for eDP connector. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: hersen wu <hersenxs.wu@xxxxxxx> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1804,6 +1804,7 @@ static void update_connector_ext_caps(st struct amdgpu_display_manager *dm; struct drm_connector *conn_base; struct amdgpu_device *adev; + struct dc_link *link = NULL; static const u8 pre_computed_values[] = { 50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 65, 66, 68, 69, 71, 72, 74, 75, 77, 79, 81, 82, 84, 86, 88, 90, 92, 94, 96, 98}; @@ -1811,6 +1812,10 @@ static void update_connector_ext_caps(st if (!aconnector || !aconnector->dc_link) return; + link = aconnector->dc_link; + if (link->connector_signal != SIGNAL_TYPE_EDP) + return; + conn_base = &aconnector->base; adev = conn_base->dev->dev_private; dm = &adev->dm;