[PATCH 11/25] drm/amd/display: Add dc cap to restrict VSR downscaling src size

[Harry Wentland]

From: Xingyue Tao <xingyue.tao at amd.com>

- Adds int max_downscale_src_width in dc struct
- Checks and does not support if downscale size is more than 4k (width > 3840)

Signed-off-by: Xingyue Tao <xingyue.tao at amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu at amd.com>
Acked-by: Harry Wentland <harry.wentland at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc.h              |  1 +
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c | 16 +++++++++++-----
 .../drm/amd/display/dc/dcn10/dcn10_resource.c    |  1 +
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 1c39c9996a04..08b29a742921 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -203,6 +203,7 @@ struct dc_debug {
 	bool clock_trace;
 	bool validation_trace;
 	bool bandwidth_calcs_trace;
+	int max_downscale_src_width;
 
 	/* stutter efficiency related */
 	bool disable_stutter;
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c
index 20796da36de4..2da138904312 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c
@@ -145,12 +145,18 @@ bool dpp_get_optimal_number_of_taps(
 	else
 		pixel_width = scl_data->viewport.width;
 
-	/* Some ASICs does not support  FP16 scaling, so we reject modes require this*/
 	if (scl_data->viewport.width  != scl_data->h_active &&
-		scl_data->viewport.height != scl_data->v_active &&
-		dpp->caps->dscl_data_proc_format == DSCL_DATA_PRCESSING_FIXED_FORMAT &&
-		scl_data->format == PIXEL_FORMAT_FP16)
-		return false;
+		scl_data->viewport.height != scl_data->v_active) {
+
+		/* Some ASICs does not support  FP16 scaling, so we reject modes require this*/
+		if (dpp->caps->dscl_data_proc_format == DSCL_DATA_PRCESSING_FIXED_FORMAT &&
+			scl_data->format == PIXEL_FORMAT_FP16)
+			return false;
+
+		if (dpp->ctx->dc->debug.max_downscale_src_width != 0 &&
+			scl_data->viewport.width > dpp->ctx->dc->debug.max_downscale_src_width)
+			return false;
+	}
 
 	/* TODO: add lb check */
 
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
index 16c84e9ee33b..f69f3a54f001 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
@@ -447,6 +447,7 @@ static const struct dc_debug debug_defaults_drv = {
 		.performance_trace = false,
 		.az_endpoint_mute_only = true,
 		.recovery_enabled = false, /*enable this by default after testing.*/
+		.max_downscale_src_width = 3840,
 };
 
 static const struct dc_debug debug_defaults_diags = {
-- 
2.17.0