[PATCH 21/25] drm/amd/display: Add missing HBM support and raise Vega20's uclk.

sunpeng.li at amd.com sunpeng.li at amd.com
Tue Sep 10 13:54:41 UTC 2019


From: Zhan Liu <zhan.liu at amd.com>

[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 at amd.com>
Reviewed-by: Roman Li <Roman.Li at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 .../display/dc/clk_mgr/dce110/dce110_clk_mgr.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git 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
index ee32d2c19305..36277bca0326 100644
--- 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_requirements(
 	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_requirements(
 	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,
-- 
2.22.0



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