On 2018-07-04 04:40 PM, mikita.lipski at amd.com wrote: > From: Mikita Lipski <mikita.lipski at amd.com> > > [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, Doesn't this update timing_out->display_color_depth? We should probably name this something else, maybe "pick_max_supported_color_depth" or something similar. Harry > + 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, >
