[PATCH v4] drm/amd/display: fix PSR-SU/DSC interoperability support

From: Hamza Mahfooz
Date: Thu Jan 05 2023 - 17:24:03 EST


Currently, there are issues with enabling PSR-SU + DSC. This stems from
the fact that DSC imposes a slice height on transmitted video data and
we are not conforming to that slice height in PSR-SU regions. So, pass
slice_height into su_y_granularity to feed the DSC slice height into
PSR-SU code.

Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
---
v2: move code to modules/power.
v3: use ASSERT() instead of WARN() and add a condition that clarifies
that PSR-SU + DSC can only be enabled on an eDP connection.
v4: change the logic again to allow non-eDP links to pass the first
filter in psr_su_set_y_granularity() (this allows us to maintain
the v1/v2 behaviour, while still being clear as to the fact that we
only care about eDP connections).
---
.../drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c | 3 ++
.../amd/display/modules/power/power_helpers.c | 31 +++++++++++++++++++
.../amd/display/modules/power/power_helpers.h | 3 ++
3 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
index 26291db0a3cf..872d06fe1436 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
@@ -122,6 +122,9 @@ bool amdgpu_dm_link_setup_psr(struct dc_stream_state *stream)
psr_config.allow_multi_disp_optimizations =
(amdgpu_dc_feature_mask & DC_PSR_ALLOW_MULTI_DISP_OPT);

+ if (!psr_su_set_y_granularity(dc, link, stream, &psr_config))
+ return false;
+
ret = dc_link_setup_psr(link, stream, &psr_config, &psr_context);

}
diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
index 9b5d9b2c9a6a..cf4fa87c7db6 100644
--- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
+++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
@@ -916,3 +916,34 @@ bool mod_power_only_edp(const struct dc_state *context, const struct dc_stream_s
{
return context && context->stream_count == 1 && dc_is_embedded_signal(stream->signal);
}
+
+bool psr_su_set_y_granularity(struct dc *dc, struct dc_link *link,
+ struct dc_stream_state *stream,
+ struct psr_config *config)
+{
+ uint16_t pic_height;
+ uint8_t slice_height;
+
+ if ((link->connector_signal & SIGNAL_TYPE_EDP) &&
+ (!dc->caps.edp_dsc_support ||
+ link->panel_config.dsc.disable_dsc_edp ||
+ !link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT ||
+ !stream->timing.dsc_cfg.num_slices_v))
+ return true;
+
+ pic_height = stream->timing.v_addressable +
+ stream->timing.v_border_top + stream->timing.v_border_bottom;
+ slice_height = pic_height / stream->timing.dsc_cfg.num_slices_v;
+
+ if (slice_height) {
+ if (config->su_y_granularity &&
+ (slice_height % config->su_y_granularity)) {
+ ASSERT(0);
+ return false;
+ }
+
+ config->su_y_granularity = slice_height;
+ }
+
+ return true;
+}
diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.h b/drivers/gpu/drm/amd/display/modules/power/power_helpers.h
index 316452e9dbc9..bb16b37b83da 100644
--- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.h
+++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.h
@@ -59,4 +59,7 @@ void mod_power_calc_psr_configs(struct psr_config *psr_config,
const struct dc_stream_state *stream);
bool mod_power_only_edp(const struct dc_state *context,
const struct dc_stream_state *stream);
+bool psr_su_set_y_granularity(struct dc *dc, struct dc_link *link,
+ struct dc_stream_state *stream,
+ struct psr_config *config);
#endif /* MODULES_POWER_POWER_HELPERS_H_ */
--
2.38.1