[PATCH v3 3/3] drm: clean cached display info

[Jose Abreu]

Hi Shashank,


On 21-12-2016 15:29, Shashank Sharma wrote:
> This patch adds a small helper function, which clears the cached
> information about a hot-pluggable display, from connector. On event
> This will run on event of a hot-unplug, keeping the connector's display
> info up-to-date, avoiding any errors due to invalid cached data.
>
> Cc: Jose Abreu <joabreu at synopsys.com>
>
> Suggested-by: Jose Abreu <joabreu at synopsys.com>
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> ---
>  drivers/gpu/drm/drm_probe_helper.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> index 7cff91e..9e97b45 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -164,6 +164,18 @@ void drm_kms_helper_poll_enable_locked(struct drm_device *dev)
>  }
>  
>  /**
> + * drm_helper_clear_display_info - clean cached display information for
> + * hot pluggable displays, on event of hot-unplug
> + * @connector: connector under event
> + */
> +void drm_helper_clear_display_info(struct drm_connector *connector)
> +{
> +	struct drm_display_info *info = &connector->display_info;
> +
> +	memset(info, 0, sizeof(*info));
> +}
> +
> +/**
>   * drm_helper_probe_single_connector_modes - get complete set of display modes
>   * @connector: connector to probe
>   * @maxX: max width for modes
> @@ -288,6 +300,14 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
>  		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
>  			connector->base.id, connector->name);
>  		drm_mode_connector_update_edid_property(connector, NULL);
> +
> +		/*
> +		 * Connector status change to disconnected, time to clean
> +		 * cached display information
> +		 */
> +		if (connector->status == connector_status_disconnected)
> +			drm_helper_clear_display_info(connector);
> +

I don't know if this is the right place to do this because it is
a helper and I don't know if it is used by all the drivers. We
may need something more general that is always called when
probing modes, or force drivers that don't use the helper to use
the drm_helper_clear_display_info function. As I told you before,
I'm new to dri-devel so we need more comments.

Best regards,
Jose Miguel Abreu

>  		verbose_prune = false;
>  		goto prune;
>  	}