drm/amd/display: Add polling method to handle MST reply packet

[Why]
Specific TBT4 dock doesn't send out short HPD to notify source
that IRQ event DOWN_REP_MSG_RDY is set. Which violates the spec
and cause source can't send out streams to mst sinks.

[How]
To cover this misbehavior, add an additional polling method to detect
DOWN_REP_MSG_RDY is set. HPD driven handling method is still kept.
Just hook up our handler to drm mgr->cbs->poll_hpd_irq().

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jerry Zuo <jerry.zuo@amd.com>
Acked-by: Alan Liu <haoping.liu@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 11 insertions, 0 deletions

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 1e4ede1e57ab..37c820ab0fdb 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
@@ -49,6 +49,13 @@
 #define PBN_FEC_OVERHEAD_MULTIPLIER_8B_10B	1031
 #define PBN_FEC_OVERHEAD_MULTIPLIER_128B_132B	1000
 
+enum mst_msg_ready_type {
+	NONE_MSG_RDY_EVENT = 0,
+	DOWN_REP_MSG_RDY_EVENT = 1,
+	UP_REQ_MSG_RDY_EVENT = 2,
+	DOWN_OR_UP_MSG_RDY_EVENT = 3
+};
+
 struct amdgpu_display_manager;
 struct amdgpu_dm_connector;
 
@@ -61,6 +68,10 @@ void amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager *dm,
 void
 dm_dp_create_fake_mst_encoders(struct amdgpu_device *adev);
 
+void dm_handle_mst_sideband_msg_ready_event(
+	struct drm_dp_mst_topology_mgr *mgr,
+	enum mst_msg_ready_type msg_rdy_type);
+
 struct dsc_mst_fairness_vars {
 	int pbn;
 	bool dsc_enabled;