• Anthony Koo's avatar
    drm/amd/display: do not power on eDP power rail early · 45021f8e
    Anthony Koo authored
    [Why]
    Modern Standby may toggle display adapter state between D0
    and D3 state unpredictably.
    But events that cause transition to D0 are not always resulting
    in a display light up scenario.
    
    Modern eDP panels should be able to power on panel logic
    quickly upon VDD going high. Based on spec, the T3 time
    between VDD on and HPD high can be between 0 and 80 ms.
    
    Doing any tricky sorts of optimization by powering on panel
    VDD early during D0 transition on can negatively impact other
    features due to unnecessary power drain and toggling when
    final system state does not intend for the panel to be lit up.
    
    We need OEMs to source higher end panels that have T3 time
    close to 0 if they want quick S3/Modern Standby resume times.
    
    [How]
    Remove panel VDD power on in init_hw
    Signed-off-by: default avatarAnthony Koo <Anthony.Koo@amd.com>
    Reviewed-by: default avatarTony Cheng <Tony.Cheng@amd.com>
    Acked-by: default avatarLeo Li <sunpeng.li@amd.com>
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    45021f8e
dcn20_hwseq.c 58.1 KB