drm/amd/display: fix image corruption with ODM 2:1 DSC 2 slice

[ Upstream commit df8e34a ]

[why]
When combining two or more pipes in DSC mode, there will always be more
than 1 slice per line.  In this case, as per DSC rules, the sink device
is expecting that the ICH is reset at the end of each slice line (i.e.
ICH_RESET_AT_END_OF_LINE must be configured based on the number of
slices at the output of ODM).  It is recommended that software set
ICH_RESET_AT_END_OF_LINE = 0xF for each DSC in the ODM combine.  However
the current code only set ICH_RESET_AT_END_OF_LINE = 0xF when number of
slice per DSC engine is greater than 1 instead of number of slice per
output after ODM combine.

[how]
Add is_odm in dsc config. Set ICH_RESET_AT_END_OF_LINE = 0xF if either
is_odm or number of slice per DSC engine is greater than 1.

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Nikola Cornij <Nikola.Cornij@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Wenjing Liu

drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c

@@ -400,6 +400,7 @@ void dp_set_dsc_on_stream(struct pipe_ctx *pipe_ctx, bool enable)
 		dsc_cfg.pic_height = stream->timing.v_addressable + stream->timing.v_border_top + stream->timing.v_border_bottom;
 		dsc_cfg.pixel_encoding = stream->timing.pixel_encoding;
 		dsc_cfg.color_depth = stream->timing.display_color_depth;
+		dsc_cfg.is_odm = pipe_ctx->next_odm_pipe ? true : false;
 		dsc_cfg.dc_dsc_cfg = stream->timing.dsc_cfg;
 		ASSERT(dsc_cfg.dc_dsc_cfg.num_slices_h % opp_cnt == 0);
 		dsc_cfg.dc_dsc_cfg.num_slices_h /= opp_cnt;
@@ -504,6 +505,7 @@ bool dp_set_dsc_pps_sdp(struct pipe_ctx *pipe_ctx, bool enable)
 		dsc_cfg.pic_height = stream->timing.v_addressable + stream->timing.v_border_top + stream->timing.v_border_bottom;
 		dsc_cfg.pixel_encoding = stream->timing.pixel_encoding;
 		dsc_cfg.color_depth = stream->timing.display_color_depth;
+		dsc_cfg.is_odm = pipe_ctx->next_odm_pipe ? true : false;
 		dsc_cfg.dc_dsc_cfg = stream->timing.dsc_cfg;
 
 		DC_LOG_DSC(" ");

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c

@@ -351,6 +351,7 @@ static bool dsc_prepare_config(const struct dsc_config *dsc_cfg, struct dsc_reg_
 	dsc_reg_vals->pps.block_pred_enable = dsc_cfg->dc_dsc_cfg.block_pred_enable;
 	dsc_reg_vals->pps.line_buf_depth = dsc_cfg->dc_dsc_cfg.linebuf_depth;
 	dsc_reg_vals->alternate_ich_encoding_en = dsc_reg_vals->pps.dsc_version_minor == 1 ? 0 : 1;
+	dsc_reg_vals->ich_reset_at_eol = (dsc_cfg->is_odm || dsc_reg_vals->num_slices_h > 1) ? 0xF : 0;
 
 	// TODO: in addition to validating slice height (pic height must be divisible by slice height),
 	// see what happens when the same condition doesn't apply for slice_width/pic_width.
@@ -513,7 +514,6 @@ static void dsc_update_from_dsc_parameters(struct dsc_reg_values *reg_vals, cons
 		reg_vals->pps.rc_buf_thresh[i] = reg_vals->pps.rc_buf_thresh[i] >> 6;
 
 	reg_vals->rc_buffer_model_size = dsc_params->rc_buffer_model_size;
-	reg_vals->ich_reset_at_eol = reg_vals->num_slices_h == 1 ? 0 : 0xf;
 }
 
 static void dsc_write_to_registers(struct display_stream_compressor *dsc, const struct dsc_reg_values *reg_vals)

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -2275,6 +2275,7 @@ static bool dcn20_validate_dsc(struct dc *dc, struct dc_state *new_ctx)
 				+ stream->timing.v_border_bottom;
 		dsc_cfg.pixel_encoding = stream->timing.pixel_encoding;
 		dsc_cfg.color_depth = stream->timing.display_color_depth;
+		dsc_cfg.is_odm = pipe_ctx->next_odm_pipe ? true : false;
 		dsc_cfg.dc_dsc_cfg = stream->timing.dsc_cfg;
 		dsc_cfg.dc_dsc_cfg.num_slices_h /= opp_cnt;
 

drivers/gpu/drm/amd/display/dc/inc/hw/dsc.h

@@ -36,6 +36,7 @@ struct dsc_config {
 	uint32_t pic_height;
 	enum dc_pixel_encoding pixel_encoding;
 	enum dc_color_depth color_depth;  /* Bits per component */
+	bool is_odm;
 	struct dc_dsc_config dc_dsc_cfg;
 };