[PATCH 15/16] drm/amd/display: Fix Vega10 lightup on S3 resume

[sunpeng.li at amd.com]

From: Roman Li <Roman.Li at amd.com>

[Why]
There have been a few reports of Vega10 display remaining blank
after S3 resume. The regression is caused by workaround for mode
change on Vega10 - skip set_bandwidth if stream count is 0.
As a result we skipped dispclk reset on suspend, thus on resume
we may skip the clock update assuming it hasn't been changed.
On some systems it causes display blank or 'out of range'.

[How]
Revert "drm/amd/display: Fix Vega10 black screen after mode change"
Verified that it hadn't cause mode change regression.

Signed-off-by: Roman Li <Roman.Li at amd.com>
Reviewed-by: Sun peng Li <Sunpeng.Li at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c |  2 +-
 drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.h |  5 -----
 drivers/gpu/drm/amd/display/dc/dce120/dce120_hw_sequencer.c | 12 ------------
 3 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
index 6b7cccc..b75ede5 100644
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
@@ -2537,7 +2537,7 @@ static void pplib_apply_display_requirements(
 	dc->prev_display_config = *pp_display_cfg;
 }
 
-void dce110_set_bandwidth(
+static void dce110_set_bandwidth(
 		struct dc *dc,
 		struct dc_state *context,
 		bool decrease_allowed)
diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.h
index e4c5db7..d6db3db 100644
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.h
@@ -68,11 +68,6 @@ void dce110_fill_display_configs(
 	const struct dc_state *context,
 	struct dm_pp_display_configuration *pp_display_cfg);
 
-void dce110_set_bandwidth(
-		struct dc *dc,
-		struct dc_state *context,
-		bool decrease_allowed);
-
 uint32_t dce110_get_min_vblank_time_us(const struct dc_state *context);
 
 void dp_receiver_power_ctrl(struct dc_link *link, bool on);
diff --git a/drivers/gpu/drm/amd/display/dc/dce120/dce120_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce120/dce120_hw_sequencer.c
index 5853522..eb0f5f9 100644
--- a/drivers/gpu/drm/amd/display/dc/dce120/dce120_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce120/dce120_hw_sequencer.c
@@ -244,17 +244,6 @@ static void dce120_update_dchub(
 	dh_data->dchub_info_valid = false;
 }
 
-static void dce120_set_bandwidth(
-		struct dc *dc,
-		struct dc_state *context,
-		bool decrease_allowed)
-{
-	if (context->stream_count <= 0)
-		return;
-
-	dce110_set_bandwidth(dc, context, decrease_allowed);
-}
-
 void dce120_hw_sequencer_construct(struct dc *dc)
 {
 	/* All registers used by dce11.2 match those in dce11 in offset and
@@ -263,6 +252,5 @@ void dce120_hw_sequencer_construct(struct dc *dc)
 	dce110_hw_sequencer_construct(dc);
 	dc->hwss.enable_display_power_gating = dce120_enable_display_power_gating;
 	dc->hwss.update_dchub = dce120_update_dchub;
-	dc->hwss.set_bandwidth = dce120_set_bandwidth;
 }
 
-- 
2.7.4