[PATCH] drm/atmel-hlcdc: Fix output initialization

[Sean Paul]

On Thu, May 18, 2017 at 02:43:07PM +0200, Alexandre Belloni wrote:
> On 18/05/2017 at 14:35:21 +0200, Boris Brezillon wrote:
> > drm_of_find_panel_or_bridge() is expecting np to point to the encoder
> > node, not the bridge or panel this encoder is feeding.
> > Moreover, the endpoint parameter passed to drm_of_find_panel_or_bridge()
> > is always set to zero, which prevents us from probing all outputs.
> > 
> > We also move the atmel_hlcdc_rgb_output allocation after the
> > panel/bridge detection to avoid useless allocations.
> > 
> > Reported-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
> Tested-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>

Applied to -misc-fixes, thank you

Sean

> 
> > Fixes: ebc944613567 ("drm: convert drivers to use drm_of_find_panel_or_bridge")
> > Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> > ---
> >  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 36 +++++++++---------------
> >  1 file changed, 14 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> > index 65a3bd7a0c00..423dda2785d4 100644
> > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> > @@ -152,8 +152,7 @@ static const struct drm_connector_funcs atmel_hlcdc_panel_connector_funcs = {
> >  	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> >  };
> >  
> > -static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
> > -				       const struct device_node *np)
> > +static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
> >  {
> >  	struct atmel_hlcdc_dc *dc = dev->dev_private;
> >  	struct atmel_hlcdc_rgb_output *output;
> > @@ -161,6 +160,11 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
> >  	struct drm_bridge *bridge;
> >  	int ret;
> >  
> > +	ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint,
> > +					  &panel, &bridge);
> > +	if (ret)
> > +		return ret;
> > +
> >  	output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
> >  	if (!output)
> >  		return -EINVAL;
> > @@ -177,10 +181,6 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
> >  
> >  	output->encoder.possible_crtcs = 0x1;
> >  
> > -	ret = drm_of_find_panel_or_bridge(np, 0, 0, &panel, &bridge);
> > -	if (ret)
> > -		return ret;
> > -
> >  	if (panel) {
> >  		output->connector.dpms = DRM_MODE_DPMS_OFF;
> >  		output->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
> > @@ -220,22 +220,14 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
> >  
> >  int atmel_hlcdc_create_outputs(struct drm_device *dev)
> >  {
> > -	struct device_node *remote;
> > -	int ret = -ENODEV;
> > -	int endpoint = 0;
> > -
> > -	while (true) {
> > -		/* Loop thru possible multiple connections to the output */
> > -		remote = of_graph_get_remote_node(dev->dev->of_node, 0,
> > -						  endpoint++);
> > -		if (!remote)
> > -			break;
> > -
> > -		ret = atmel_hlcdc_attach_endpoint(dev, remote);
> > -		of_node_put(remote);
> > -		if (ret)
> > -			return ret;
> > -	}
> > +	int endpoint, ret = 0;
> > +
> > +	for (endpoint = 0; !ret; endpoint++)
> > +		ret = atmel_hlcdc_attach_endpoint(dev, endpoint);
> > +
> > +	/* At least one device was successfully attached.*/
> > +	if (ret == -ENODEV && endpoint)
> > +		return 0;
> >  
> >  	return ret;
> >  }
> > -- 
> > 2.7.4
> > 
> 
> -- 
> Alexandre Belloni, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com

-- 
Sean Paul, Software Engineer, Google / Chromium OS