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| author | Mikita Lipski <mikita.lipski@amd.com> | 2019-09-20 22:44:56 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2020-01-10 02:07:46 +0300 |
| commit | 5b03f9d86880711441c5681244d352212460a595 (patch) | |
| tree | 5d68dab858a86e32557aa33de34b8cb6ed1becdd /drivers/gpu/drm/drm_dp_mst_topology.c | |
| parent | c2bc1b6eabe65d6bf26a892d803907dca9097311 (diff) | |
| download | linux-5b03f9d86880711441c5681244d352212460a595.tar.xz | |
drm/dp_mst: Add new quirk for Synaptics MST hubs
Synaptics DP1.4 hubs (BRANCH_ID 0x90CC24) do not
support virtual DPCD registers, but do support DSC.
The DSC caps can be read from the physical aux,
like in SST DSC. These hubs have many different
DEVICE_IDs. Add a new quirk to detect this case.
v2: Fix error when checking return of drm_dp_read_desc
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: David Francis <David.Francis@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 2b20caa4b7e3..480c71a00cf2 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -5148,6 +5148,7 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) { struct drm_dp_mst_port *immediate_upstream_port; struct drm_dp_mst_port *fec_port; + struct drm_dp_desc desc = { 0 }; u8 endpoint_fec; u8 endpoint_dsc; @@ -5201,6 +5202,32 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) return &port->aux; /* + * Synaptics quirk + * Applies to ports for which: + * - Physical aux has Synaptics OUI + * - DPv1.4 or higher + * - Port is on primary branch device + * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) + */ + if (drm_dp_read_desc(port->mgr->aux, &desc, true)) + return NULL; + + if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && + port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && + port->parent == port->mgr->mst_primary) { + u8 downstreamport; + + if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT, + &downstreamport, 1) < 0) + return NULL; + + if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) && + ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK) + != DP_DWN_STRM_PORT_TYPE_ANALOG)) + return port->mgr->aux; + } + + /* * The check below verifies if the MST sink * connected to the GPU is capable of DSC - * therefore the endpoint needs to be |