[PATCH v2 4/4] drm/sun4i: Update mixer's internal registers after initialization

[roman.stratiienko at globallogic.com]

From: Roman Stratiienko <roman.stratiienko at globallogic.com>

At system start blink of u-boot ghost framebuffer can be observed.
Fix it.

Fixes: 9d75b8c0b999 ("drm/sun4i: add support for Allwinner DE2 mixers")
Signed-off-by: Roman Stratiienko <roman.stratiienko at globallogic.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec at siol.net>
---
v2:
- Picked 'Reviewed-by' line
- Added 'Fixes' line
---
 drivers/gpu/drm/sun4i/sun8i_mixer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c
index 5d90a95ff855..86711d8a9c84 100644
--- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
@@ -576,6 +576,9 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
 	regmap_update_bits(mixer->engine.regs, SUN8I_MIXER_BLEND_PIPE_CTL(base),
 			   SUN8I_MIXER_BLEND_PIPE_CTL_EN_MSK, 0);
 
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_GLOBAL_DBUFF,
+		     SUN8I_MIXER_GLOBAL_DBUFF_ENABLE);
+
 	return 0;
 
 err_disable_bus_clk:
-- 
2.17.1