Re: [RFC 4/4] drm/sun4i: Update mixer's internal registers after initialization

Jernej Škrabec
2019-12-29T09:25:20Z

Hi!

Dne sobota, 28. december 2019 ob 21:28:18 CET je
roman.stratiienko@globallogic.com napisal(a):
> From: Roman Stratiienko <roman.stratiienko@globallogic.com>
>
> At system start blink of u-boot ghost framebuffer can be observed.
> Fix it.

Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>

Please note that U-Boot to Linux handover may not be without issues. I noticed
that in some cases, HDMI EDID readout is broken. I guess already initialized
HDMI controller doesn't like to be reinitialized. Or it may have something to
do with the fact that U-Boot HDMI driver sets I2C timing and Linux kernel uses
default one.

Best regards,
Jernej

>
> Signed-off-by: Roman Stratiienko <roman.stratiienko@globallogic.com>
> ---
> 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 da84fccf7784..b906b8cc464e
> 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
> @@ -588,6 +588,9 @@ 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;
>