[PATCH] drm/sysfs: Send out uevent when connector->force changes

[Daniel Vetter]

On Thu, Nov 19, 2015 at 09:06:04PM +0000, Chris Wilson wrote:
> On Thu, Nov 19, 2015 at 05:46:50PM +0100, Daniel Vetter wrote:
> > To avoid even more code duplication punt this all to the probe worker,
> > which needs some slight adjustment to also generate a uevent when the
> > status has changed to due connector->force.
> > 
> > v2: Instead of running the output_poll_work (which is kinda the wrong
> > thing and a layering violation since it's an internal of the probe
> > helpers), or calling ->detect (which is again a layering violation
> > since it's used only by probe helpers) just call the official
> > ->fill_modes function, like a GET_CONNECTOR ioctl call.
> > 
> > v3: Restore the accidentally removed forced-probe for echo "detect" >
> > force.
> > 
> 
> > diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> > index 9ac4ffa6cce3..df66d9447cb0 100644
> > --- a/drivers/gpu/drm/drm_sysfs.c
> > +++ b/drivers/gpu/drm/drm_sysfs.c
> > @@ -167,47 +167,35 @@ static ssize_t status_store(struct device *device,
> >  {
> >  	struct drm_connector *connector = to_drm_connector(device);
> >  	struct drm_device *dev = connector->dev;
> > -	enum drm_connector_status old_status;
> > +	enum drm_connector_force old_force;
> >  	int ret;
> >  
> >  	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
> >  	if (ret)
> >  		return ret;
> >  
> > -	old_status = connector->status;
> > +	old_force = connector->force;
> >  
> > -	if (sysfs_streq(buf, "detect")) {
> > +	if (sysfs_streq(buf, "detect"))
> >  		connector->force = 0;
> > -		connector->status = connector->funcs->detect(connector, true);
> > -	} else if (sysfs_streq(buf, "on")) {
> > +	else if (sysfs_streq(buf, "on"))
> >  		connector->force = DRM_FORCE_ON;
> > -	} else if (sysfs_streq(buf, "on-digital")) {
> > +	else if (sysfs_streq(buf, "on-digital"))
> >  		connector->force = DRM_FORCE_ON_DIGITAL;
> > -	} else if (sysfs_streq(buf, "off")) {
> > +	else if (sysfs_streq(buf, "off"))
> >  		connector->force = DRM_FORCE_OFF;
> > -	} else
> > +	else
> >  		ret = -EINVAL;
> >  
> > -	if (ret == 0 && connector->force) {
> > -		if (connector->force == DRM_FORCE_ON ||
> > -		    connector->force == DRM_FORCE_ON_DIGITAL)
> > -			connector->status = connector_status_connected;
> > -		else
> > -			connector->status = connector_status_disconnected;
> > -		if (connector->funcs->force)
> > -			connector->funcs->force(connector);
> > -	}
> > -
> > -	if (old_status != connector->status) {
> > -		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
> > +	if (old_force != connector->force || !connector->force) {
> > +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
> >  			      connector->base.id,
> >  			      connector->name,
> > -			      old_status, connector->status);
> > +			      old_force, connector->force);
> >  
> > -		dev->mode_config.delayed_event = true;
> > -		if (dev->mode_config.poll_enabled)
> > -			schedule_delayed_work(&dev->mode_config.output_poll_work,
> > -					      0);
> > +		connector->funcs->fill_modes(connector,
> > +					     dev->mode_config.max_width,
> > +					     dev->mode_config.max_height);
> 
> This now does fill_modes() before we call detect(). We rely on the
> ordering of detect() before doing fill_modes() as in many cases we use
> the EDID gathered in detect() to generate the modes (if I am not
> mistaken, I think we merged those patches to cache the EDID for a
> detection cycle).

->fill_modes = drm_helper_probe_single_connector_modes which then calls
->detect. By going this way we avoid duplicating the "send uevent if
anything changed" logic all over the place, and ->detect becomes purely a
helper internal callback to get at the mode list for hotpluggeable
outputs.

Yes this means that ->detect should become a helper function, but that's
quite an invasive change.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch