[PATCH] dt-bindings: display: Start the info graphics with HS/VS change

[Sam Ravnborg]

Hi Marek.

On Tue, Feb 21, 2023 at 09:04:07PM +0100, Marek Vasut wrote:
> The VS signal change is synchronized to HS signal change, start the
> info graphics with that event, instead of having that event occur in
> the middle of it.
> 
> Scope trace of DPI bus with HS/VS active HIGH looks as follows:
>          ________________...__
> VS...___/__         __        \______...
> HS...___/  \_______/  \__...__/  \___...
>         ^                        ^
> 	|                        |
>         |    Used to start here -'
> 	|
> 	'--- Start info graphics here
> 
> Signed-off-by: Marek Vasut <marex at denx.de>

I recall being annoyed about this before.
Reviewed-by: Sam Ravnborg <sam at ravnborg.org>

> ---
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: David Airlie <airlied at gmail.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Cc: devicetree at vger.kernel.org
> Cc: dri-devel at lists.freedesktop.org
> ---
>  .../bindings/display/panel/panel-timing.yaml  | 46 +++++++++----------
>  1 file changed, 23 insertions(+), 23 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/panel/panel-timing.yaml b/Documentation/devicetree/bindings/display/panel/panel-timing.yaml
> index 0d317e61edd8f..aea69b84ca5d8 100644
> --- a/Documentation/devicetree/bindings/display/panel/panel-timing.yaml
> +++ b/Documentation/devicetree/bindings/display/panel/panel-timing.yaml
> @@ -17,29 +17,29 @@ description: |
>  
>    The parameters are defined as seen in the following illustration.
>  
> -  +----------+-------------------------------------+----------+-------+
> -  |          |        ^                            |          |       |
> -  |          |        |vback_porch                 |          |       |
> -  |          |        v                            |          |       |
> -  +----------#######################################----------+-------+
> -  |          #        ^                            #          |       |
> -  |          #        |                            #          |       |
> -  |  hback   #        |                            #  hfront  | hsync |
> -  |   porch  #        |       hactive              #  porch   |  len  |
> -  |<-------->#<-------+--------------------------->#<-------->|<----->|
> -  |          #        |                            #          |       |
> -  |          #        |vactive                     #          |       |
> -  |          #        |                            #          |       |
> -  |          #        v                            #          |       |
> -  +----------#######################################----------+-------+
> -  |          |        ^                            |          |       |
> -  |          |        |vfront_porch                |          |       |
> -  |          |        v                            |          |       |
> -  +----------+-------------------------------------+----------+-------+
> -  |          |        ^                            |          |       |
> -  |          |        |vsync_len                   |          |       |
> -  |          |        v                            |          |       |
> -  +----------+-------------------------------------+----------+-------+
> +  +-------+----------+-------------------------------------+----------+
> +  |       |          |        ^                            |          |
> +  |       |          |        |vsync_len                   |          |
> +  |       |          |        v                            |          |
> +  +-------+----------+-------------------------------------+----------+
> +  |       |          |        ^                            |          |
> +  |       |          |        |vback_porch                 |          |
> +  |       |          |        v                            |          |
> +  +-------+----------#######################################----------+
> +  |       |          #        ^                            #          |
> +  |       |          #        |                            #          |
> +  | hsync |  hback   #        |                            #  hfront  |
> +  |  len  |   porch  #        |       hactive              #  porch   |
> +  |<----->|<-------->#<-------+--------------------------->#<-------->|
> +  |       |          #        |                            #          |
> +  |       |          #        |vactive                     #          |
> +  |       |          #        |                            #          |
> +  |       |          #        v                            #          |
> +  +-------+----------#######################################----------+
> +  |       |          |        ^                            |          |
> +  |       |          |        |vfront_porch                |          |
> +  |       |          |        v                            |          |
> +  +-------+----------+-------------------------------------+----------+
>  
>  
>    The following is the panel timings shown with time on the x-axis.
> -- 
> 2.39.1