[PATCH] drm: Lighten sysfs connector 'status'

[Daniel Vetter]

On Thu, Mar 05, 2015 at 09:50:31AM +0000, Chris Wilson wrote:
> 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"?

Imo ok as-is, digital is just a substate used by some drivers to decide
between dvi-d and dvi-i modes. For most connectors it's the same as plain
"on".
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch