Hi! We’re building an embedded system where our display requires interlaced video.
I’ve noticed that the fallback EDID (default_720p_edid in edid.c in the display driver) defines support for 720p, 1080i, 480p and 576p, but xrandr only lists the progressive formats as being available on HDMI-0 (ie, 720p, 480p and 476p are available, 1080i is not), and we cannot override that through xrandr addmode commands.
We replaced the fallback EDID with a custom EDID, that defined support for 480i, 480p, 576i, and 576p. With the custom EDID, only 480p and 576p formats were listed as available for HDMI-0, and again we couldn’t override to add the interlaced formats with xrandr addmode.
The Parker technical reference manual lists interlaced as being supported, CONFIG_TEGRA_DC_INTERLACE=y in our kernel config, and the t186_feature_entries_a found in nvdisp_config.c seem to indicate TEGRA_DC_FEATURE_FIELD_TYPE is supported for all 6 windows.
How can I enable interpolation? We need 480i and/or 576i for our system, and I haven’t seen anything in the documentation to say it isn’t supported.