[PATCH v4 01/15] drm/panel: panel-simple: validate panel description

[Laurent Pinchart]

Hi Sam,

Thank you for the patch.

On Sun, Jul 26, 2020 at 10:33:10PM +0200, Sam Ravnborg wrote:
> Warn if we detect a panel with incomplete/wrong description.
> This is inspired by a similar patch by Laurent that introduced checks
> for LVDS panels - this extends the checks to the remaining type of
> connectors.
> 
> This is known to warn for some of the existing panels but added
> despite this as we need help from people using the panels to
> add the missing info.
> The checks are not complete but will catch the most common mistakes.
> 
> The checks at the same time serves as documentation for the minimum

s/serves/serve/

> required description for a panel.
> 
> The checks uses dev_warn() as we know this will hit. WARN() was
> too noisy at the moment for anything else than LVDS.
> 
> v2:
>   - Use dev_warn (Laurent)
>   - Check for empty bus_flags
> 
> Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> ---
>  drivers/gpu/drm/panel/panel-simple.c | 41 ++++++++++++++++++++++++++--
>  1 file changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 54323515ca2c..a8d68102931e 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -500,6 +500,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>  	struct panel_simple *panel;
>  	struct display_timing dt;
>  	struct device_node *ddc;
> +	u32 bus_flags;
>  	int err;
>  
>  	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
> @@ -549,8 +550,12 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>  			panel_simple_parse_panel_timing_node(dev, panel, &dt);
>  	}
>  
> -	if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) {
> -		/* Catch common mistakes for LVDS panels. */
> +	/* Catch common mistakes for panels. */
> +	switch (desc->connector_type) {
> +	case 0:
> +		dev_warn(dev, "Specify missing connector_type\n");
> +		break;
> +	case DRM_MODE_CONNECTOR_LVDS:
>  		WARN_ON(desc->bus_flags &
>  			~(DRM_BUS_FLAG_DE_LOW |
>  			  DRM_BUS_FLAG_DE_HIGH |
> @@ -564,6 +569,38 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>  		WARN_ON((desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_SPWG ||
>  			 desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA) &&
>  			desc->bpc != 8);
> +		break;
> +	case DRM_MODE_CONNECTOR_eDP:
> +		if (desc->bus_format == 0)
> +			dev_warn(dev, "Specify missing bus_format\n");
> +		if (desc->bpc != 6 && desc->bpc != 8)
> +			dev_warn(dev, "Expected bpc in {6,8} but got: %d\n", desc->bpc);

bpc is unsigned, so s/%d/%u/

> +		break;
> +	case DRM_MODE_CONNECTOR_DSI:
> +		if (desc->bpc != 6 && desc->bpc != 8)
> +			dev_warn(dev, "Expected bpc in {6,8} but got: %d\n", desc->bpc);

Same here.

> +		break;
> +	case DRM_MODE_CONNECTOR_DPI:
> +		bus_flags = DRM_BUS_FLAG_DE_LOW |
> +			    DRM_BUS_FLAG_DE_HIGH |
> +			    DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE |
> +			    DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
> +			    DRM_BUS_FLAG_DATA_MSB_TO_LSB |
> +			    DRM_BUS_FLAG_DATA_LSB_TO_MSB |
> +			    DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE |
> +			    DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
> +		if (desc->bus_flags & ~bus_flags)
> +			dev_warn(dev, "Unexpected bus_flags(%d)\n", desc->bus_flags & ~bus_flags);
> +		if (!(desc->bus_flags & bus_flags))
> +			dev_warn(dev, "Specify missing bus_flags\n");
> +		if (desc->bus_format == 0)
> +			dev_warn(dev, "Specify missing bus_format\n");
> +		if (desc->bpc != 6 && desc->bpc != 8)
> +			dev_warn(dev, "Expected bpc in {6,8} but got: %d\n", desc->bpc);

And here too.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +		break;
> +	default:
> +		dev_warn(dev, "Specify a valid connector_type: %d\n", desc->connector_type);
> +		break;
>  	}
>  
>  	drm_panel_init(&panel->base, dev, &panel_simple_funcs,

-- 
Regards,

Laurent Pinchart