4.19-stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Kazlauskas nicholas.kazlauskas@amd.com
[ Upstream commit 481f576c6c21bf0446eaa23623ef0262e9a5387c ]
[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 the dce110 set bandwidth codepath this was removed for power saving considerations.
That change caused display corruption under certain hardware configurations with Vega10.
[How]
The 15% DISPCLK increase is brought back but only on dce110 for now. This is should be a temporary workaround until the root cause is sorted out for why this occurs on Vega (or other ASICs, if reported).
Tested-by: Nick Sarnie sarnex@gentoo.org Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Reviewed-by: Harry Wentland Harry.Wentland@amd.com Acked-by: Bhawanpreet Lakha Bhawanpreet.Lakha@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clocks.c @@ -466,6 +466,9 @@ static void dce12_update_clocks(struct d { struct dm_pp_clock_for_voltage_req clock_voltage_req = {0};
+ /* TODO: Investigate why this is needed to fix display corruption. */ + new_clocks->dispclk_khz = new_clocks->dispclk_khz * 115 / 100; + if (should_set_clock(safe_to_lower, new_clocks->dispclk_khz, dccg->clks.dispclk_khz)) { clock_voltage_req.clk_type = DM_PP_CLOCK_TYPE_DISPLAY_CLK; clock_voltage_req.clocks_in_khz = new_clocks->dispclk_khz;