Hi, On Tue, 13 Oct 2026 at 23:52, Cristian Ciocaltea <[email protected]> wrote: > @@ -229,7 +230,14 @@ dw_hdmi_qp_rockchip_encoder_atomic_check(struct > drm_encoder *encoder, > } > > phy_cfg.hdmi.tmds_char_rate = conn_state->hdmi.tmds_char_rate; > - phy_cfg.hdmi.bpc = conn_state->hdmi.output_bpc; > + /* > + * YUV422 always transmits two 12-bit components per clock cycle, > + * regardless of the color depth, which from a rate perspective is > + * equivalent to three 8-bit RGB components. Force 8 bpc here to > + * keep the PHY PLL output aligned with the TMDS character rate. > + */ > + phy_cfg.hdmi.bpc = (s->output_mode == ROCKCHIP_OUT_MODE_YUV422 ? > + 8 : conn_state->hdmi.output_bpc);
Same question as for the VOP2: why only special-case YUV422 when YUV420 also needs special treatment? And presumably in a way which can't just be mashed into bpc, because the maths doesn't work. So would this be better off being handled as a separate output-mode adjustment? Cheers, Daniel
