drm/amd/display: Force delay after DP receive power up

[Why]
Some sprcified monitor scalar cannot recognize timing
change on demand. Once the link phy disable and enable
during a short period then the Sink protection mechanism
could keep the screen in blank and cannot be recoverred.

[How]
To add 100ms delay between enable link phy and link training.

Signed-off-by: Martin Tsai <martin.tsai@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index fe4fd66..97703f8 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1559,9 +1559,10 @@ bool perform_link_training_with_retries(
                        pipe_ctx->clock_source->id,
                        link_setting);
 
-               if (stream->sink_patches.dppowerup_delay > 0) {
-                       int delay_dp_power_up_in_ms = stream->sink_patches.dppowerup_delay;
-
+               if ((link && link->dc->debug.dppowerup_delay > 0) || stream->sink_patches.dppowerup_delay > 0) {
+                       int delay_dp_power_up_in_ms =
+                               (link->dc->debug.dppowerup_delay >= stream->sink_patches.dppowerup_delay) ?
+                               link->dc->debug.dppowerup_delay : stream->sink_patches.dppowerup_delay;
                        msleep(delay_dp_power_up_in_ms);
                }
 

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 8cdbfa1..9138adf 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -498,6 +498,7 @@ struct dc_debug_options {
        bool usbc_combo_phy_reset_wa;
        bool disable_dsc;
        bool enable_dram_clock_change_one_display_vactive;
+       unsigned int dppowerup_delay;
 };
 
 struct dc_debug_data {