From 04c2d1eb93882970d49afeab078b3f1e1275c5ab Mon Sep 17 00:00:00 2001 From: Joshua Aberback Date: Thu, 21 Jan 2021 02:33:31 -0500 Subject: [PATCH] drm/amd/display: Better handling of dummy p-state table [Why] Some scenarios where we use a UCLK frequency in between dummy p-state table entries result in a p-state hang, due to the table not having a close enough match, so the default DPM0 latency is used, which can be too long to support dummy p-state switching in these scenarios. [How] - old: match if current freq is within +- margin of table entry - new: find largest table entry that is lower than current freq + margin - lower than DPM0 will still use DPM0 Signed-off-by: Joshua Aberback Reviewed-by: Jun Lei Acked-by: Anson Jacob Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/dc/dcn30/dcn30_resource.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c index 22ae6a547cd3f..8d0f663489ac5 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c @@ -2189,17 +2189,15 @@ static noinline void dcn30_calculate_wm_and_dlg_fp( unsigned int min_dram_speed_mts = context->bw_ctx.dml.vba.DRAMSpeed; unsigned int min_dram_speed_mts_margin = 160; - context->bw_ctx.dml.soc.dram_clock_change_latency_us = dc->clk_mgr->bw_params->dummy_pstate_table[0].dummy_pstate_latency_us; - if (context->bw_ctx.dml.vba.DRAMClockChangeSupport[vlevel][context->bw_ctx.dml.vba.maxMpcComb] == dm_dram_clock_change_unsupported) min_dram_speed_mts = dc->clk_mgr->bw_params->clk_table.entries[dc->clk_mgr->bw_params->clk_table.num_entries - 1].memclk_mhz * 16; - for (i = 3; i > 0; i--) { - if ((min_dram_speed_mts + min_dram_speed_mts_margin > dc->clk_mgr->bw_params->dummy_pstate_table[i].dram_speed_mts) && - (min_dram_speed_mts - min_dram_speed_mts_margin < dc->clk_mgr->bw_params->dummy_pstate_table[i].dram_speed_mts)) - context->bw_ctx.dml.soc.dram_clock_change_latency_us = dc->clk_mgr->bw_params->dummy_pstate_table[i].dummy_pstate_latency_us; - } + /* find largest table entry that is lower than dram speed, but lower than DPM0 still uses DPM0 */ + for (i = 3; i > 0; i--) + if (min_dram_speed_mts + min_dram_speed_mts_margin > dc->clk_mgr->bw_params->dummy_pstate_table[i].dram_speed_mts) + break; + context->bw_ctx.dml.soc.dram_clock_change_latency_us = dc->clk_mgr->bw_params->dummy_pstate_table[i].dummy_pstate_latency_us; context->bw_ctx.dml.soc.sr_enter_plus_exit_time_us = dc->clk_mgr->bw_params->wm_table.nv_entries[WM_C].dml_input.sr_enter_plus_exit_time_us; context->bw_ctx.dml.soc.sr_exit_time_us = dc->clk_mgr->bw_params->wm_table.nv_entries[WM_C].dml_input.sr_exit_time_us; } -- 2.39.5