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authorFangzhi Zuo <Jerry.Zuo@amd.com>2023-02-24 21:45:21 +0300
committerAlex Deucher <alexander.deucher@amd.com>2023-03-30 00:21:05 +0300
commitf4f3b7dedbe849e780c779ba67365bb1db0d8637 (patch)
tree44591a952b8e0f698fc7cc72c624c6609ef8bd1b
parent197b6b60ae7bc51dd0814953c562833143b292aa (diff)
downloadlinux-f4f3b7dedbe849e780c779ba67365bb1db0d8637.tar.xz
drm/amd/display: Add DSC Support for Synaptics Cascaded MST Hub
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 <hersenxs.wu@amd.com> Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com> Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c19
-rw-r--r--drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h12
2 files changed, 31 insertions, 0 deletions
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 e25e1b2bf194..30de0aa084d8 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
@@ -212,6 +212,21 @@ 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;
@@ -235,6 +250,10 @@ static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnecto
needs_dsc_aux_workaround(aconnector->dc_link))
aconnector->dsc_aux = &aconnector->mst_root->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 97fd70df531b..0b5750202e73 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
@@ -34,6 +34,18 @@
#define SYNAPTICS_RC_OFFSET 0x4BC
#define SYNAPTICS_RC_DATA 0x4C0
+#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;