Commit a316db72 authored by Mario Kleiner's avatar Mario Kleiner Committed by Alex Deucher
Browse files

drm/amd/display: Increase linebuffer pixel depth to 36bpp. 



Testing with the photometer shows that at least Raven Ridge DCN-1.0
does not achieve more than 10 bpc effective output precision with a
16 bpc unorm surface of type SURFACE_PIXEL_FORMAT_GRPH_ABGR16161616,
unless linebuffer depth is increased from LB_PIXEL_DEPTH_30BPP to
LB_PIXEL_DEPTH_36BPP. Otherwise precision gets truncated somewhere
to 10 bpc effective depth.

Strangely this increase was not needed on Polaris11 DCE-11.2 during
testing to get 12 bpc effective precision. It also is not needed for
fp16 framebuffers.

Tested on DCN-1.0 and DCE-11.2.

Signed-off-by: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 050cd3d6

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

+5 −2
Original line number Diff line number Diff line
@@ -1039,9 +1039,12 @@ bool resource_build_scaling_params(struct pipe_ctx *pipe_ctx) 
	/*

	 * LB calculations depend on vp size, h/v_active and scaling ratios

	 * Setting line buffer pixel depth to 24bpp yields banding

	 * on certain displays, such as the Sharp 4k

	 * on certain displays, such as the Sharp 4k. 36bpp is needed

	 * to support SURFACE_PIXEL_FORMAT_GRPH_ARGB16161616 and

	 * SURFACE_PIXEL_FORMAT_GRPH_ABGR16161616 with actual > 10 bpc

	 * precision on at least DCN display engines.

	 */

	pipe_ctx->plane_res.scl_data.lb_params.depth = LB_PIXEL_DEPTH_30BPP;

	pipe_ctx->plane_res.scl_data.lb_params.depth = LB_PIXEL_DEPTH_36BPP;

	pipe_ctx->plane_res.scl_data.lb_params.alpha_en = plane_state->per_pixel_alpha;



	if (pipe_ctx->plane_res.xfm != NULL)

drivers/gpu/drm/amd/display/dc/dce/dce_transform.c

+4 −2
Original line number Diff line number Diff line
@@ -1647,7 +1647,8 @@ void dce_transform_construct( 
	xfm_dce->lb_pixel_depth_supported =

			LB_PIXEL_DEPTH_18BPP |

			LB_PIXEL_DEPTH_24BPP |

			LB_PIXEL_DEPTH_30BPP;

			LB_PIXEL_DEPTH_30BPP |

			LB_PIXEL_DEPTH_36BPP;



	xfm_dce->lb_bits_per_entry = LB_BITS_PER_ENTRY;

	xfm_dce->lb_memory_size = LB_TOTAL_NUMBER_OF_ENTRIES; /*0x6B0*/
@@ -1675,7 +1676,8 @@ void dce60_transform_construct( 
	xfm_dce->lb_pixel_depth_supported =

			LB_PIXEL_DEPTH_18BPP |

			LB_PIXEL_DEPTH_24BPP |

			LB_PIXEL_DEPTH_30BPP;

			LB_PIXEL_DEPTH_30BPP |

			LB_PIXEL_DEPTH_36BPP;



	xfm_dce->lb_bits_per_entry = LB_BITS_PER_ENTRY;

	xfm_dce->lb_memory_size = LB_TOTAL_NUMBER_OF_ENTRIES; /*0x6B0*/

drivers/gpu/drm/amd/display/dc/dce110/dce110_transform_v.c

+2 −1
Original line number Diff line number Diff line
@@ -708,7 +708,8 @@ bool dce110_transform_v_construct( 
	xfm_dce->lb_pixel_depth_supported =

			LB_PIXEL_DEPTH_18BPP |

			LB_PIXEL_DEPTH_24BPP |

			LB_PIXEL_DEPTH_30BPP;

			LB_PIXEL_DEPTH_30BPP |

			LB_PIXEL_DEPTH_36BPP;



	xfm_dce->prescaler_on = true;

	xfm_dce->lb_bits_per_entry = LB_BITS_PER_ENTRY;

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c

+2 −1
Original line number Diff line number Diff line
@@ -568,7 +568,8 @@ void dpp1_construct( 
	dpp->lb_pixel_depth_supported =

		LB_PIXEL_DEPTH_18BPP |

		LB_PIXEL_DEPTH_24BPP |

		LB_PIXEL_DEPTH_30BPP;

		LB_PIXEL_DEPTH_30BPP |

		LB_PIXEL_DEPTH_36BPP;



	dpp->lb_bits_per_entry = LB_BITS_PER_ENTRY;

	dpp->lb_memory_size = LB_TOTAL_NUMBER_OF_ENTRIES; /*0x1404*/

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

+1 −1
Original line number Diff line number Diff line
@@ -2593,7 +2593,7 @@ static void update_scaler(struct pipe_ctx *pipe_ctx) 
			pipe_ctx->plane_state->per_pixel_alpha && pipe_ctx->bottom_pipe;



	pipe_ctx->plane_res.scl_data.lb_params.alpha_en = per_pixel_alpha;

	pipe_ctx->plane_res.scl_data.lb_params.depth = LB_PIXEL_DEPTH_30BPP;

	pipe_ctx->plane_res.scl_data.lb_params.depth = LB_PIXEL_DEPTH_36BPP;

	/* scaler configuration */

	pipe_ctx->plane_res.dpp->funcs->dpp_set_scaler(

			pipe_ctx->plane_res.dpp, &pipe_ctx->plane_res.scl_data);