From: Samson Tam <[email protected]> [Why] Fixes issue when we have a display connected using a passive dongle and then emulate over it using a DP connection at 1 x 1.62 Ghz. System hangs because register bus returns back 0xFFFFFFFF for all register reads after setting register DIG_BE_CNTL in dcn10_link_encoder_connect_dig_be_to_fe(). Hang occurs later when trying to do a register read.
[How] At the start of the emulation, dc_link_set_preferred_link_settings() and dp_retrain_link_dp_test() is called, even though it is connected using a passive dongle. Add an extra condition in dp_retrain_link_dp_test() to check for link->dongle_max_pix_clk > 0. This is the only way we know if the connection is using passive dongle so we don't retrain DP. Signed-off-by: Samson Tam <[email protected]> Reviewed-by: Jun Lei <[email protected]> Acked-by: Leo Li <[email protected]> --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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 0918c334f0e2..02a18f6aa009 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -2998,8 +2998,10 @@ void dc_link_set_preferred_link_settings(struct dc *dc, /* Retrain with preferred link settings only relevant for * DP signal type + * Check for non-DP signal or if passive dongle present */ - if (!dc_is_dp_signal(link->connector_signal)) + if (!dc_is_dp_signal(link->connector_signal) || + link->dongle_max_pix_clk > 0) return; for (i = 0; i < MAX_PIPES; i++) { -- 2.22.0 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
