• Ville Syrjälä's avatar
    drm/edid: Allow HDMI infoframe without VIC or S3D · f1781e9b
    Ville Syrjälä authored
    Appedix F of HDMI 2.0 says that some HDMI sink may fail to switch from
    3D to 2D mode in a timely fashion if the source simply stops sending the
    HDMI infoframe. The suggested workaround is to keep sending the
    infoframe even when strictly not necessary (ie. no VIC and no S3D).
    HDMI 1.4 does allow for this behaviour, stating that sending the
    infoframe is optional in this case.
    
    The infoframe was first specified in HDMI 1.4, so in theory sinks
    predating that may not appreciate us sending an uknown infoframe
    their way. To avoid regressions let's try to determine if the sink
    supports the infoframe or not. Unfortunately there's no direct way
    to do that, so instead we'll just check if we managed to parse any
    HDMI 1.4 4k or stereo modes from the EDID, and if so we assume the
    sink will accept the infoframe. Also if the EDID contains the HDMI
    2.0 HDMI Forum VSDB we can assume the sink is prepared to receive
    the infoframe.
    
    v2: Fix getting has_hdmi_infoframe from display_info
        Always fail constructing the infoframe if the display
        possibly can't handle it
    
    Cc: Shashank Sharma <shashank.sharma@intel.com>
    Cc: Andrzej Hajda <a.hajda@samsung.com>
    Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
    Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
    Reviewed-by: default avatarShashank Sharma <shashank.sharma@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20171113170427.4150-3-ville.syrjala@linux.intel.com
    f1781e9b
drm_edid.h 15.1 KB