Re: [PATCH 2/4] drm/panel: otm8009a: fix glitches by moving backlight enable to otm8009a_enable()

[Vincent ABRIOU <vincent.abriou@st.com>]

Hi Philippe,

Reviewed-by: Vincent Abriou <vincent.abriou@st.com>

BR
Vincent

On 04/23/2018 04:10 PM, Philippe Cornu wrote:
> The backlight 1st update was in the otm8009a_prepare() function
> for a bad reason: backlight was not working in video mode and the
> otm8009a_prepare() is in command mode for the init sequence. As the
> backlight is now fixed (no lpm), it is good to put it back in the
> otm8009a_enable() function, avoiding also image glitches visible
> on some "slow" devices.
> 
> Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
> ---
>   drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> index 0fd2e0144d2b..de4a16d5275c 100644
> --- a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> +++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> @@ -330,13 +330,6 @@ static int otm8009a_prepare(struct drm_panel *panel)
>   
>   	ctx->prepared = true;
>   
> -	/*
> -	 * Power on the backlight. Note: end-user still controls brightness
> -	 * Note: ctx->prepared must be true before updating the backlight.
> -	 */
> -	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
> -	backlight_update_status(ctx->bl_dev);
> -
>   	return 0;
>   }
>   
> @@ -344,6 +337,16 @@ static int otm8009a_enable(struct drm_panel *panel)
>   {
>   	struct otm8009a *ctx = panel_to_otm8009a(panel);
>   
> +	if (ctx->enabled)
> +		return 0;
> +
> +	/*
> +	 * Power on the backlight. Note: end-user still controls brightness
> +	 * Note: ctx->prepared must be true before updating the backlight.
> +	 */
> +	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
> +	backlight_update_status(ctx->bl_dev);
> +
>   	ctx->enabled = true;
>   
>   	return 0;
>