[PATCH 22/37] drm/amd/display: Skip SST ACT polling when sink_count is 0

[Aurabindo Pillai]

From: George Shen <george.s...@amd.com>

[Why]
Upon disconnecting a UHBR SST display, the disconnection and the
SetTimings to disable the display can occur such that link_set_dpms_off
occurs after the disconnection has already processed
(link->type is dc_connection_none). Thus, the AUX related
operations should be skipped when clearing the payload allocation table.

Reviewed-by: Wenjing Liu <wenjing....@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pil...@amd.com>
Signed-off-by: George Shen <george.s...@amd.com>
Tested-by: Daniel Wheeler <daniel.whee...@amd.com>
---
 drivers/gpu/drm/amd/display/dc/link/link_dpms.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c 
b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index 938421e02770..087423be3151 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -1158,12 +1158,13 @@ static bool poll_for_allocation_change_trigger(struct 
dc_link *link)
        int i;
        const int act_retries = 30;
        enum act_return_status result = ACT_FAILED;
+       enum dc_connection_type display_connected = (link->type != 
dc_connection_none);
        union payload_table_update_status update_status = {0};
        union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX];
        union lane_align_status_updated lane_status_updated;
        DC_LOGGER_INIT(link->ctx->logger);
 
-       if (link->aux_access_disabled)
+       if (!display_connected || link->aux_access_disabled)
                return true;
        for (i = 0; i < act_retries; i++) {
                get_lane_status(link, link->cur_link_settings.lane_count, 
dpcd_lane_status, &lane_status_updated);
@@ -1512,6 +1513,7 @@ static bool write_128b_132b_sst_payload_allocation_table(
        union payload_table_update_status update_status = { 0 };
        const uint32_t max_retries = 30;
        uint32_t retries = 0;
+       enum dc_connection_type display_connected = (link->type != 
dc_connection_none);
        DC_LOGGER_INIT(link->ctx->logger);
 
        if (allocate)   {
@@ -1529,7 +1531,7 @@ static bool write_128b_132b_sst_payload_allocation_table(
        proposed_table->stream_allocations[0].slot_count = req_slot_count;
        proposed_table->stream_allocations[0].vcp_id = vc_id;
 
-       if (link->aux_access_disabled)
+       if (!display_connected || link->aux_access_disabled)
                return true;
 
        /// Write DPCD 2C0 = 1 to start updating
-- 
2.44.0