From fb0fe920469ac52acc315069ca9a3aa56ebd5395 Mon Sep 17 00:00:00 2001 From: Chris Park Date: Sat, 12 Sep 2020 13:06:59 -0400 Subject: [PATCH] drm/amd/display: TMDS Fallback transition [Why] HDMI requires fallback to TMDS by redetection in order to switch PHY settings. This avoids black out when link training fail during mode setting, link quality update, disable driver sequence. [How] Allow driver to redetect HDMI displays based on retraining or fallback mechanism. Signed-off-by: Chris Park Reviewed-by: Aric Cyr Acked-by: Qingqing Zhuo Signed-off-by: Alex Deucher --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 13 +++++++++++++ drivers/gpu/drm/amd/display/dc/dc_link.h | 2 ++ 2 files changed, 15 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 9d7333a36fac..db741e47d194 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -159,7 +159,20 @@ static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnecto u8 dsc_caps[16] = { 0 }; aconnector->dsc_aux = drm_dp_mst_dsc_aux_for_port(port); +#if defined(CONFIG_HP_HOOK_WORKAROUND) + /* + * drm_dp_mst_dsc_aux_for_port() will return NULL for certain configs + * because it only check the dsc/fec caps of the "port variable" and not the dock + * + * This case will return NULL: DSC capabe MST dock connected to a non fec/dsc capable display + * + * Workaround: explicitly check the use case above and use the mst dock's aux as dsc_aux + * + */ + if (!aconnector->dsc_aux && !port->parent->port_parent) + aconnector->dsc_aux = &aconnector->mst_port->dm_dp_aux.aux; +#endif if (!aconnector->dsc_aux) return false; diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h index e002ef706e1d..266b93a705d5 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_link.h +++ b/drivers/gpu/drm/amd/display/dc/dc_link.h @@ -237,6 +237,8 @@ enum dc_detect_reason { DETECT_REASON_BOOT, DETECT_REASON_HPD, DETECT_REASON_HPDRX, + DETECT_REASON_FALLBACK, + DETECT_REASON_RETRAIN }; bool dc_link_detect(struct dc_link *dc_link, enum dc_detect_reason reason); -- GitLab