From 7051d51f1241d02a9db159485bddfe508427ab01 Mon Sep 17 00:00:00 2001 From: Fangzhi Zuo Date: Fri, 24 Feb 2023 13:45:21 -0500 Subject: [PATCH] drm/amd/display: Add DSC Support for Synaptics Cascaded MST Hub commit f4f3b7dedbe849e780c779ba67365bb1db0d8637 upstream. Traditional synaptics hub has one MST branch device without virtual dpcd. Synaptics cascaded hub has two chained MST branch devices. DSC decoding is performed via root MST branch device, instead of the second MST branch device. Reviewed-by: Hersen Wu Acked-by: Qingqing Zhuo Signed-off-by: Fangzhi Zuo Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 19 +++++++++++++++++++ .../display/amdgpu_dm/amdgpu_dm_mst_types.h | 12 ++++++++++++ 2 files changed, 31 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 d617e98afb76..767b3d31c720 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 @@ -164,6 +164,21 @@ static bool needs_dsc_aux_workaround(struct dc_link *link) return false; } +bool is_synaptics_cascaded_panamera(struct dc_link *link, struct drm_dp_mst_port *port) +{ + u8 branch_vendor_data[4] = { 0 }; // Vendor data 0x50C ~ 0x50F + + if (drm_dp_dpcd_read(port->mgr->aux, DP_BRANCH_VENDOR_SPECIFIC_START, &branch_vendor_data, 4) == 4) { + if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 && + IS_SYNAPTICS_CASCADED_PANAMERA(link->dpcd_caps.branch_dev_name, branch_vendor_data)) { + DRM_INFO("Synaptics Cascaded MST hub\n"); + return true; + } + } + + return false; +} + static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnector) { struct dc_sink *dc_sink = aconnector->dc_sink; @@ -185,6 +200,10 @@ static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnecto needs_dsc_aux_workaround(aconnector->dc_link)) aconnector->dsc_aux = &aconnector->mst_port->dm_dp_aux.aux; + /* synaptics cascaded MST hub case */ + if (!aconnector->dsc_aux && is_synaptics_cascaded_panamera(aconnector->dc_link, port)) + aconnector->dsc_aux = port->mgr->aux; + if (!aconnector->dsc_aux) return false; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h index b38bd68121ce..5d60e2bf0bd8 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h @@ -26,6 +26,18 @@ #ifndef __DAL_AMDGPU_DM_MST_TYPES_H__ #define __DAL_AMDGPU_DM_MST_TYPES_H__ +#define DP_BRANCH_VENDOR_SPECIFIC_START 0x50C + +/** + * Panamera MST Hub detection + * Offset DPCD 050Eh == 0x5A indicates cascaded MST hub case + * Check from beginning of branch device vendor specific field (050Ch) + */ +#define IS_SYNAPTICS_PANAMERA(branchDevName) (((int)branchDevName[4] & 0xF0) == 0x50 ? 1 : 0) +#define BRANCH_HW_REVISION_PANAMERA_A2 0x10 +#define SYNAPTICS_CASCADED_HUB_ID 0x5A +#define IS_SYNAPTICS_CASCADED_PANAMERA(devName, data) ((IS_SYNAPTICS_PANAMERA(devName) && ((int)data[2] == SYNAPTICS_CASCADED_HUB_ID)) ? 1 : 0) + struct amdgpu_display_manager; struct amdgpu_dm_connector;