[PATCH] drm: Lighten sysfs connector 'status'

[Chris Wilson]

On Thu, Mar 05, 2015 at 09:45:41AM +0000, Chris Wilson wrote:
> Since the beginning, sysfs/connector/status has done a heavyweight
> detection of the current connector status. But no user, such as upowerd
> or logind, has ever desired to initiate a probe. Move the probing into a
> new attribute so that existing readers get the behaviour they desire.
> 
> v2: David Herrmann suggested using "echo detect > /sys/.../status" to
> trigger the probing, which is a fine idea. This extends that to also
> allow the user to apply the force detection overrides at runtime.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: David Herrmann <dh.herrmann at gmail.com>
> Cc: Dave Airlie <airled at redhat.com>
> Cc: Alex Deucher <alexdeucher at gmail.com>
> ---
>  drivers/gpu/drm/drm_sysfs.c | 58 ++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 52 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> index 5c99d3773212..c1ae57ec7afa 100644
> --- a/drivers/gpu/drm/drm_sysfs.c
> +++ b/drivers/gpu/drm/drm_sysfs.c
> @@ -166,23 +166,69 @@ void drm_sysfs_destroy(void)
>  /*
>   * Connector properties
>   */
> -static ssize_t status_show(struct device *device,
> +static ssize_t status_store(struct device *device,
>  			   struct device_attribute *attr,
> -			   char *buf)
> +			   const char *buf, size_t count)
>  {
>  	struct drm_connector *connector = to_drm_connector(device);
> -	enum drm_connector_status status;
> +	enum drm_connector_status old_status;
>  	int ret;
>  
>  	ret = mutex_lock_interruptible(&connector->dev->mode_config.mutex);
>  	if (ret)
>  		return ret;
>  
> -	status = connector->funcs->detect(connector, true);
> +	old_status = connector->status;
> +
> +	if (strcmp(buf, "detect") == 0) {
> +		connector->force = 0;
> +		connector->funcs->detect(connector, true);

This has to be:
   connector->status = connector->funcs->detect(connector, true);

> +	} else if (strcmp(buf, "on") == 0) {
> +		connector->force = DRM_FORCE_ON;
> +	} else if (strcmp(buf, "on-digital") == 0) {
> +		connector->force = DRM_FORCE_ON_DIGITAL;

Is it worth reducing this to just "digital"?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre