Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-10 15:58:47 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

drm/amd/display: Add DSC Support for Synaptics Cascaded MST Hub

Browse Source 
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
This commit is contained in:
Fangzhi Zuo 2023-02-24 13:45:21 -05:00 committed by Alex Deucher
parent 197b6b60ae
commit f4f3b7dedb
2 changed files with 31 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
View File

@ -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;

12
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
View File

@ -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;