[PATCH 1/2] drm: Add a new connector property for link status

[Manasi Navare]

Chris,

Would you be able to make the necessary changes in the suerspace
driver so I can do some testing tomorrow?

Manasi

On Tue, Oct 25, 2016 at 06:16:34PM -0700, Manasi Navare wrote:
> A new optional connector property is added for keeping
> track of whether the link is good (link training passed) or
> link is bad (link training  failed). If the link status property
> is Bad, then userspace should fire off a new modeset at the current
> mode even if there have not been any changes in the mode list
> or connector status.
> 
> Cc: dri-devel at lists.freedesktop.org
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> ---
>  drivers/gpu/drm/drm_connector.c | 32 ++++++++++++++++++++++++++++++++
>  include/drm/drm_connector.h     |  1 +
>  include/drm/drm_crtc.h          |  6 ++++++
>  include/uapi/drm/drm_mode.h     |  4 ++++
>  4 files changed, 43 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 2db7fb5..b4ce19f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -588,6 +588,11 @@ int drm_display_info_set_bus_formats(struct drm_display_info *info,
>  DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
>  		 drm_tv_subconnector_enum_list)
>  
> +static const struct drm_prop_enum_list drm_link_status_enum_list[] = {
> +	{ DRM_MODE_LINK_STATUS_GOOD, "Good" },
> +	{ DRM_MODE_LINK_STATUS_BAD, "Bad" },
> +};
> +
>  int drm_connector_create_standard_properties(struct drm_device *dev)
>  {
>  	struct drm_property *prop;
> @@ -845,6 +850,33 @@ int drm_mode_create_suggested_offset_properties(struct drm_device *dev)
>  EXPORT_SYMBOL(drm_mode_create_suggested_offset_properties);
>  
>  /**
> + * drm_mode_create_link_status_property - Create link status property
> + * @dev: DRM device
> + *
> + * Called by a driver the first time it's needed, must be attached to desired
> + * connectors.
> + * This property is used to indicate whether link sttaus is Good or Bad as
> + * a result fo link training
> + */
> +int drm_mode_create_link_status_property(struct drm_device *dev)
> +{
> +	struct drm_property *link_status;
> +
> +	if (dev->mode_config.link_status_property)
> +		return 0;
> +
> +	link_status =
> +		drm_property_create_enum(dev, 0, "link-status",
> +					 drm_link_status_enum_list,
> +					 ARRAY_SIZE(drm_link_status_enum_list));
> +
> +	dev->mode_config.scaling_mode_property = link_status;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(drm_mode_create_link_status_property);
> +
> +/**
>   * drm_mode_connector_set_path_property - set tile property on connector
>   * @connector: connector to set property on.
>   * @path: path to use for property; must not be NULL.
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index fc9d475..7234c0c 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -759,6 +759,7 @@ int drm_mode_create_tv_properties(struct drm_device *dev,
>  int drm_mode_create_scaling_mode_property(struct drm_device *dev);
>  int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
>  int drm_mode_create_suggested_offset_properties(struct drm_device *dev);
> +int drm_mode_create_link_status_property(struct drm_device *dev);
>  
>  int drm_mode_connector_set_path_property(struct drm_connector *connector,
>  					 const char *path);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index fa1aa21..3e9c833 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -1343,6 +1343,12 @@ struct drm_mode_config {
>  	 */
>  	struct drm_property *suggested_y_property;
>  
> +	/**
> +	 * @link_status_property: Optional connector property for link status
> +	 * of the connector as a result of link training.
> +	 */
> +	 struct drm_property *link_status_property;
> +
>  	/* dumb ioctl parameters */
>  	uint32_t preferred_depth, prefer_shadow;
>  
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index 084b50a..f1b0afd 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -121,6 +121,10 @@
>  #define DRM_MODE_DIRTY_ON       1
>  #define DRM_MODE_DIRTY_ANNOTATE 2
>  
> +/* Link Status options */
> +#define DRM_MODE_LINK_STATUS_GOOD	0
> +#define DRM_MODE_LINK_STATUS_BAD	1
> +
>  struct drm_mode_modeinfo {
>  	__u32 clock;
>  	__u16 hdisplay;
> -- 
> 1.9.1
>