From ea117312ea9f4113c4a8f4571a9ba189248721c4 Mon Sep 17 00:00:00 2001 From: Thomas Anderson Date: Mon, 2 Dec 2019 13:47:13 -0800 Subject: [PATCH] drm/amd/display: Reduce HDMI pixel encoding if max clock is exceeded For high-res (8K) or HFR (4K120) displays, using uncompressed pixel formats like YCbCr444 would exceed the bandwidth of HDMI 2.0, so the "interesting" modes would be disabled, leaving only low-res or low framerate modes. This change lowers the pixel encoding to 4:2:2 or 4:2:0 if the max TMDS clock is exceeded. Verified that 8K30 and 4K120 are now available and working with a Samsung Q900R over an HDMI 2.0b link from a Radeon 5700. Reviewed-by: Harry Wentland Signed-off-by: Thomas Anderson Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 45 ++++++++++--------- 1 file changed, 23 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 70e33ea8711a..c4a0d0e5050a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -3704,27 +3704,21 @@ get_output_color_space(const struct dc_crtc_timing *dc_crtc_timing) return color_space; } -static void reduce_mode_colour_depth(struct dc_crtc_timing *timing_out) -{ - if (timing_out->display_color_depth <= COLOR_DEPTH_888) - return; - - timing_out->display_color_depth--; -} - -static void adjust_colour_depth_from_display_info(struct dc_crtc_timing *timing_out, - const struct drm_display_info *info) +static bool adjust_colour_depth_from_display_info( + struct dc_crtc_timing *timing_out, + const struct drm_display_info *info) { + enum dc_color_depth depth = timing_out->display_color_depth; int normalized_clk; - if (timing_out->display_color_depth <= COLOR_DEPTH_888) - return; do { normalized_clk = timing_out->pix_clk_100hz / 10; /* YCbCr 4:2:0 requires additional adjustment of 1/2 */ if (timing_out->pixel_encoding == PIXEL_ENCODING_YCBCR420) normalized_clk /= 2; /* Adjusting pix clock following on HDMI spec based on colour depth */ - switch (timing_out->display_color_depth) { + switch (depth) { + case COLOR_DEPTH_888: + break; case COLOR_DEPTH_101010: normalized_clk = (normalized_clk * 30) / 24; break; @@ -3735,14 +3729,15 @@ static void adjust_colour_depth_from_display_info(struct dc_crtc_timing *timing_ normalized_clk = (normalized_clk * 48) / 24; break; default: - return; + /* The above depths are the only ones valid for HDMI. */ + return false; } - if (normalized_clk <= info->max_tmds_clock) - return; - reduce_mode_colour_depth(timing_out); - - } while (timing_out->display_color_depth > COLOR_DEPTH_888); - + if (normalized_clk <= info->max_tmds_clock) { + timing_out->display_color_depth = depth; + return true; + } + } while (--depth > COLOR_DEPTH_666); + return false; } static void fill_stream_properties_from_drm_display_mode( @@ -3823,8 +3818,14 @@ static void fill_stream_properties_from_drm_display_mode( stream->out_transfer_func->type = TF_TYPE_PREDEFINED; stream->out_transfer_func->tf = TRANSFER_FUNCTION_SRGB; - if (stream->signal == SIGNAL_TYPE_HDMI_TYPE_A) - adjust_colour_depth_from_display_info(timing_out, info); + if (stream->signal == SIGNAL_TYPE_HDMI_TYPE_A) { + if (!adjust_colour_depth_from_display_info(timing_out, info) && + drm_mode_is_420_also(info, mode_in) && + timing_out->pixel_encoding != PIXEL_ENCODING_YCBCR420) { + timing_out->pixel_encoding = PIXEL_ENCODING_YCBCR420; + adjust_colour_depth_from_display_info(timing_out, info); + } + } } static void fill_audio_info(struct audio_info *audio_info, -- 2.45.2