[PATCH 05/27] drm: bridge: Return NULL on error from drm_bridge_get_edid()

[Sam Ravnborg]

On Tue, May 26, 2020 at 04:14:43AM +0300, Laurent Pinchart wrote:
> The drm_bridge_get_edid() function is documented to return an error
> pointer on error. The underlying .get_edid() operation, however, returns
> NULL on error, and so do the drm_get_edid() and drm_do_get_edid()
> functions upon which .get_edid() is usually implemented. Make
> drm_bridge_get_edid() return NULL on error to be consistent.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
Acked-by: Sam Ravnborg <sam at ravnborg.org>
> ---
>  drivers/gpu/drm/bridge/ti-tfp410.c | 10 +++++++---
>  drivers/gpu/drm/drm_bridge.c       |  6 +++---
>  2 files changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
> index e3eb6364c0f7..f065a96a0917 100644
> --- a/drivers/gpu/drm/bridge/ti-tfp410.c
> +++ b/drivers/gpu/drm/bridge/ti-tfp410.c
> @@ -51,11 +51,15 @@ static int tfp410_get_modes(struct drm_connector *connector)
>  	struct edid *edid;
>  	int ret;
>  
> -	edid = drm_bridge_get_edid(dvi->next_bridge, connector);
> -	if (IS_ERR_OR_NULL(edid)) {
> -		if (edid != ERR_PTR(-ENOTSUPP))
> +	if (dvi->next_bridge->ops & DRM_BRIDGE_OP_EDID) {
> +		edid = drm_bridge_get_edid(dvi->next_bridge, connector);
> +		if (!edid)
>  			DRM_INFO("EDID read failed. Fallback to standard modes\n");
> +	} else {
> +		edid = NULL;
> +	}
>  
> +	if (!edid) {
>  		/*
>  		 * No EDID, fallback on the XGA standard modes and prefer a mode
>  		 * pretty much anything can handle.
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index afdec8e5fc68..fe1e3460b486 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -1086,16 +1086,16 @@ EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
>   *
>   * If the bridge supports output EDID retrieval, as reported by the
>   * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
> - * get the EDID and return it. Otherwise return ERR_PTR(-ENOTSUPP).
> + * get the EDID and return it. Otherwise return NULL.
>   *
>   * RETURNS:
> - * The retrieved EDID on success, or an error pointer otherwise.
> + * The retrieved EDID on success, or NULL otherwise.
>   */
>  struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
>  				 struct drm_connector *connector)
>  {
>  	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
> -		return ERR_PTR(-ENOTSUPP);
> +		return NULL;
>  
>  	return bridge->funcs->get_edid(bridge, connector);
>  }
> -- 
> Regards,
> 
> Laurent Pinchart
> 
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