[PATCH 16/16] drm/amd/display: Raise dispclk value for dce_update_clocks

[sunpeng.li at amd.com]

From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

[Why]

The DISPCLK value was previously requested to be 15% higher for all
ASICS that went through the dce110 bandwidth code path. As part of a
refactoring of dce_clocks and dce110 set_bandwidth this was removed
for power saving considerations.

This changed caused corruption under certain display configurations.
Originally thought to be Vega specific, it was also observed on Polaris.

[How]

The 15% is brought back but its placement differs from the original
patch. This boost should only be enable while DFS bypass is inactive.

This (like the Vega patch) is also a workaround that should be
removed after the root cause is identified.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c
index d42afa0..d89a097 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c
@@ -664,6 +664,11 @@ static void dce_update_clocks(struct dccg *dccg,
 			bool safe_to_lower)
 {
 	struct dm_pp_power_level_change_request level_change_req;
+	struct dce_dccg *clk_dce = TO_DCE_CLOCKS(dccg);
+
+	/* TODO: Investigate why this is needed to fix display corruption. */
+	if (!clk_dce->dfs_bypass_active)
+		new_clocks->dispclk_khz = new_clocks->dispclk_khz * 115 / 100;
 
 	level_change_req.power_level = dce_get_required_clocks_state(dccg, new_clocks);
 	/* get max clock state from PPLIB */
-- 
2.7.4