drm/amd/display: On clock init, maintain DISPCLK freq

[Description]
- On init if a display is connected, we need to maintain the DISPCLK
  frequency
- Even though DPG_EN=1, the display still requires the correct
  timing or it could cause audio corruption (if DISPCLK freq
  is reduced)
- Read the current DISPCLK freq and request the same value to ensure
  the timing is valid and unchanged
- However, add option to do a full pipe power down (including link)
  which will also avoid audio related issues
	- Disabled for the time being on dcn32

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr.h b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr.h
index 591ab1389e3b..bef843cc32a1 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr.h
@@ -293,6 +293,9 @@ struct clk_mgr_funcs {
 
 	/* Get SMU present */
 	bool (*is_smu_present)(struct clk_mgr *clk_mgr);
+
+	int (*get_dispclk_from_dentist)(struct clk_mgr *clk_mgr_base);
+
 };
 
 struct clk_mgr {