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authorDillon Varone <dillon.varone@amd.com>2024-11-01 12:00:14 -0400
committerAlex Deucher <alexander.deucher@amd.com>2024-11-11 14:05:26 -0500
commit9fc0cbcb6e45d6fc96ffd3bb7b6d6d28d693ff4d (patch)
tree7d067c9a4e437b43c966e80ab4f2e29e4d96693c
parent6825cb07b79ffeb1d90ffaa7a1227462cdca34ae (diff)
drm/amd/display: Require minimum VBlank size for stutter optimization
If the nominal VBlank is too small, optimizing for stutter can cause the prefetch bandwidth to increase drasticaly, resulting in higher clock and power requirements. Only optimize if it is >3x the stutter latency. Reviewed-by: Austin Zheng <austin.zheng@amd.com> Signed-off-by: Dillon Varone <dillon.varone@amd.com> Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 003215f962cdf2265f126a3f4c9ad20917f87fca) Cc: stable@vger.kernel.org
-rw-r--r--drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_pmo/dml2_pmo_dcn4_fams2.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_pmo/dml2_pmo_dcn4_fams2.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_pmo/dml2_pmo_dcn4_fams2.c
index 1cf9015e854a..dd9971867f74 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_pmo/dml2_pmo_dcn4_fams2.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_pmo/dml2_pmo_dcn4_fams2.c
@@ -8,6 +8,7 @@
#include "dml2_pmo_dcn4_fams2.h"
static const double MIN_VACTIVE_MARGIN_PCT = 0.25; // We need more than non-zero margin because DET buffer granularity can alter vactive latency hiding
+static const double MIN_BLANK_STUTTER_FACTOR = 3.0;
static const struct dml2_pmo_pstate_strategy base_strategy_list_1_display[] = {
// VActive Preferred
@@ -2139,6 +2140,7 @@ bool pmo_dcn4_fams2_init_for_stutter(struct dml2_pmo_init_for_stutter_in_out *in
struct dml2_pmo_instance *pmo = in_out->instance;
bool stutter_period_meets_z8_eco = true;
bool z8_stutter_optimization_too_expensive = false;
+ bool stutter_optimization_too_expensive = false;
double line_time_us, vblank_nom_time_us;
unsigned int i;
@@ -2160,10 +2162,15 @@ bool pmo_dcn4_fams2_init_for_stutter(struct dml2_pmo_init_for_stutter_in_out *in
line_time_us = (double)in_out->base_display_config->display_config.stream_descriptors[i].timing.h_total / (in_out->base_display_config->display_config.stream_descriptors[i].timing.pixel_clock_khz * 1000) * 1000000;
vblank_nom_time_us = line_time_us * in_out->base_display_config->display_config.stream_descriptors[i].timing.vblank_nom;
- if (vblank_nom_time_us < pmo->soc_bb->power_management_parameters.z8_stutter_exit_latency_us) {
+ if (vblank_nom_time_us < pmo->soc_bb->power_management_parameters.z8_stutter_exit_latency_us * MIN_BLANK_STUTTER_FACTOR) {
z8_stutter_optimization_too_expensive = true;
break;
}
+
+ if (vblank_nom_time_us < pmo->soc_bb->power_management_parameters.stutter_enter_plus_exit_latency_us * MIN_BLANK_STUTTER_FACTOR) {
+ stutter_optimization_too_expensive = true;
+ break;
+ }
}
pmo->scratch.pmo_dcn4.num_stutter_candidates = 0;
@@ -2179,7 +2186,7 @@ bool pmo_dcn4_fams2_init_for_stutter(struct dml2_pmo_init_for_stutter_in_out *in
pmo->scratch.pmo_dcn4.z8_vblank_optimizable = false;
}
- if (pmo->soc_bb->power_management_parameters.stutter_enter_plus_exit_latency_us > 0) {
+ if (!stutter_optimization_too_expensive && pmo->soc_bb->power_management_parameters.stutter_enter_plus_exit_latency_us > 0) {
pmo->scratch.pmo_dcn4.optimal_vblank_reserved_time_for_stutter_us[pmo->scratch.pmo_dcn4.num_stutter_candidates] = (unsigned int)pmo->soc_bb->power_management_parameters.stutter_enter_plus_exit_latency_us;
pmo->scratch.pmo_dcn4.num_stutter_candidates++;
}