drm/amd/display: Continue with stream enable if DP link training fails.

Not necessarily a fatal problem - some monitors will recover and show
the stream anyway if link training fails.

Signed-off-by: Ken Chalmers <ken.chalmers@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 5d374cb..ffc0eea 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1225,7 +1225,7 @@ static enum dc_status enable_link_dp(struct pipe_ctx *pipe_ctx)
                status = DC_OK;
        }
        else
-               status = DC_ERROR_UNEXPECTED;
+               status = DC_FAIL_DP_LINK_TRAINING;
 
        enable_stream_features(pipe_ctx);
 
@@ -1833,9 +1833,22 @@ void core_link_enable_stream(struct pipe_ctx *pipe_ctx)
 {
        struct core_dc *core_dc = DC_TO_CORE(pipe_ctx->stream->ctx->dc);
 
-       if (DC_OK != enable_link(pipe_ctx)) {
-                       BREAK_TO_DEBUGGER();
-                       return;
+       enum dc_status status = enable_link(pipe_ctx);
+
+       if (status != DC_OK) {
+                       dm_logger_write(pipe_ctx->stream->ctx->logger,
+                       LOG_WARNING, "enabling link %u failed: %d\n",
+                       pipe_ctx->stream->sink->link->public.link_index,
+                       status);
+
+                       /* Abort stream enable *unless* the failure was due to
+                        * DP link training - some DP monitors will recover and
+                        * show the stream anyway.
+                        */
+                       if (status != DC_FAIL_DP_LINK_TRAINING) {
+                               BREAK_TO_DEBUGGER();
+                               return;
+                       }
        }
 
        /* turn off otg test pattern if enable */

diff --git a/drivers/gpu/drm/amd/display/dc/inc/core_status.h b/drivers/gpu/drm/amd/display/dc/inc/core_status.h
index 128617d..b5759c0 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/inc/core_status.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/core_status.h
@@ -41,6 +41,7 @@ enum dc_status {
        DC_SURFACE_PIXEL_FORMAT_UNSUPPORTED = 11,
        DC_FAIL_BANDWIDTH_VALIDATE = 12, /* BW and Watermark validation */
        DC_FAIL_SCALING = 13,
+       DC_FAIL_DP_LINK_TRAINING = 14,
 
        DC_ERROR_UNEXPECTED = -1
 };