korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 00:04:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

drm/amd/display: Allow DSC on supported MST branch devices

Browse Source 
commit 94ebc03545 upstream.

[Why]
When trying to lightup two 4k60 non-DSC displays behind a branch device
that supports DSC we can't lightup both at once due to bandwidth
limitations - each requires 48 VCPI slots but we only have 63.

[How]
The workaround already exists in the code but is guarded by a CONFIG
that cannot be set by the user and shouldn't need to be.

Check for specific branch device IDs to device whether to enable
the workaround for multiple display scenarios.

Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nicholas Kazlauskas 2021-11-12 15:27:32 -05:00 committed by Greg Kroah-Hartman
parent 209d35ee34
commit 775191dd4c
1 changed files with 16 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
View File

@ -36,6 +36,8 @@
#include "dm_helpers.h"
#include "dc_link_ddc.h"
#include "ddc_service_types.h"
#include "dpcd_defs.h"
#include "i2caux_interface.h"
#if defined(CONFIG_DEBUG_FS)
@ -152,6 +154,16 @@ static const struct drm_connector_funcs dm_dp_mst_connector_funcs = {
};
#if defined(CONFIG_DRM_AMD_DC_DCN)
static bool needs_dsc_aux_workaround(struct dc_link *link)
{
if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
(link->dpcd_caps.dpcd_rev.raw == DPCD_REV_14 || link->dpcd_caps.dpcd_rev.raw == DPCD_REV_12) &&
link->dpcd_caps.sink_count.bits.SINK_COUNT >= 2)
return true;
return false;
}
static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnector)
{
struct dc_sink *dc_sink = aconnector->dc_sink;
@ -159,7 +171,7 @@ 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
@ -169,10 +181,10 @@ static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnecto
* 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)
if (!aconnector->dsc_aux && !port->parent->port_parent &&
needs_dsc_aux_workaround(aconnector->dc_link))
aconnector->dsc_aux = &aconnector->mst_port->dm_dp_aux.aux;
#endif
if (!aconnector->dsc_aux)
return false;