From: Zhan Liu zhan.liu@amd.com
commit c02d6a161395dfc0c2fdabb9e976a229017288d8 upstream.
[Why] When more than 2 displays are connected to the graphics card, only the minimum memory clock is needed. However, when more displays are connected, the minimum memory clock is not sufficient enough to support the overwhelming bandwidth. System will hang under this circumstance.
Also, the old code didn't address HBM cards, which has 2 pseudo channels. We need to add the HBM part here.
[How] When graphics card connects to 2 or more displays, switch to high memory clock. Also, choose memory multiplier based on whether its regular DRAM or HBM.
Signed-off-by: Zhan Liu zhan.liu@amd.com Reviewed-by: Roman Li Roman.Li@amd.com Acked-by: Leo Li sunpeng.li@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/amd/display/dc/clk_mgr/dce110/dce110_clk_mgr.c | 18 ++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dce110/dce110_clk_mgr.c +++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dce110/dce110_clk_mgr.c @@ -174,6 +174,10 @@ void dce11_pplib_apply_display_requireme struct dc_state *context) { struct dm_pp_display_configuration *pp_display_cfg = &context->pp_display_cfg; + int memory_type_multiplier = MEMORY_TYPE_MULTIPLIER_CZ; + + if (dc->bw_vbios && dc->bw_vbios->memory_type == bw_def_hbm) + memory_type_multiplier = MEMORY_TYPE_HBM;
pp_display_cfg->all_displays_in_sync = context->bw_ctx.bw.dce.all_displays_in_sync; @@ -186,8 +190,18 @@ void dce11_pplib_apply_display_requireme pp_display_cfg->cpu_pstate_separation_time = context->bw_ctx.bw.dce.blackout_recovery_time_us;
- pp_display_cfg->min_memory_clock_khz = context->bw_ctx.bw.dce.yclk_khz - / MEMORY_TYPE_MULTIPLIER_CZ; + /* + * TODO: determine whether the bandwidth has reached memory's limitation + * , then change minimum memory clock based on real-time bandwidth + * limitation. + */ + if (ASICREV_IS_VEGA20_P(dc->ctx->asic_id.hw_internal_rev) && (context->stream_count >= 2)) { + pp_display_cfg->min_memory_clock_khz = max(pp_display_cfg->min_memory_clock_khz, + (uint32_t) (dc->bw_vbios->high_yclk.value / memory_type_multiplier / 10000)); + } else { + pp_display_cfg->min_memory_clock_khz = context->bw_ctx.bw.dce.yclk_khz + / memory_type_multiplier; + }
pp_display_cfg->min_engine_clock_khz = determine_sclk_from_bounding_box( dc,