From: Mikita Lipski <mikita.lipski@xxxxxxx> [why] HDMI 2.0 fails to validate 4K at 60 timing with 10 bpc [how] Adding a helper function that would verify if the display depth assigned would pass a bandwidth validation. Drop the display depth by one level till calculated pixel clk is lower than maximum TMDS clk. Bugzilla: https://bugs.freedesktop.org/106959 Signed-off-by: Mikita Lipski <mikita.lipski at amd.com> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 42 +++++++++++++++++++++++ 1 file changed, 42 insertions(+) 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 ed09e36..c572e86 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2218,6 +2218,46 @@ 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 check_if_display_depth_is_supported(struct dc_crtc_timing *timing_out, + const struct drm_display_info *info) +{ + int normalized_clk; + if (timing_out->display_color_depth <= COLOR_DEPTH_888) + return; + do { + normalized_clk = timing_out->pix_clk_khz; + /* 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) { + case COLOR_DEPTH_101010: + normalized_clk = (normalized_clk * 30) / 24; + break; + case COLOR_DEPTH_121212: + normalized_clk = (normalized_clk * 36) / 24; + break; + case COLOR_DEPTH_161616: + normalized_clk = (normalized_clk * 48) / 24; + break; + default: + return; + } + if (normalized_clk <= info->max_tmds_clock) + return; + reduce_mode_colour_depth(timing_out); + + } while (timing_out->display_color_depth > COLOR_DEPTH_888); + +} /*****************************************************************************/ static void @@ -2273,6 +2313,8 @@ fill_stream_properties_from_drm_display_mode(struct dc_stream_state *stream, stream->out_transfer_func->type = TF_TYPE_PREDEFINED; stream->out_transfer_func->tf = TRANSFER_FUNCTION_SRGB; + if (stream->sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A) + check_if_display_depth_is_supported(timing_out, info); } static void fill_audio_info(struct audio_info *audio_info, -- 2.7.4
