Even though that mux is undocumented, it seems like it needs to be set to 1 when using composite, and 0 when using HDMI.
Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com> Acked-by: Chen-Yu Tsai <w...@csie.org> --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 36e25f417dc3..28da61ac9bab 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -112,16 +112,23 @@ EXPORT_SYMBOL(sun4i_tcon_enable_vblank); void sun4i_tcon_set_mux(struct sun4i_tcon *tcon, int channel, struct drm_encoder *encoder) { + u32 val; + if (!tcon->quirks->has_unknown_mux) return; if (channel != 1) return; + if (encoder->encoder_type == DRM_MODE_ENCODER_TVDAC) + val = 1; + else + val = 0; + /* * FIXME: Undocumented bits */ - regmap_write(tcon->regs, SUN4I_TCON_MUX_CTRL_REG, 1); + regmap_write(tcon->regs, SUN4I_TCON_MUX_CTRL_REG, val); } EXPORT_SYMBOL(sun4i_tcon_set_mux); -- git-series 0.9.1