Re: [PATCH] drm/bridge: Fix lvds-encoder since the panel_bridge rework.

[Archit Taneja]

On 11/15/2017 03:29 PM, Lothar WaÃmann wrote:
> Hi,
>
> On Tue, 14 Nov 2017 11:16:47 -0800 Eric Anholt wrote:
> > The panel_bridge bridge attaches to the panel's OF node, not the
> > lvds-encoder's node.  Put in a little no-op bridge of our own so that
> > our consumers can still find a bridge where they expect.
> >
> > This also fixes an unintended unregistration and leak of the
> > panel-bridge on module remove.
> >
> > Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> > Fixes: 13dfc0540a57 ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bri
> > dge.")
> > ---
> >
> > Note: I haven't actually tested this patch!  Hope it helps, though.
> >
> >   drivers/gpu/drm/bridge/lvds-encoder.c | 48 ++++++++++++++++++++++++++++++-----
> >   1 file changed, 41 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
> > index 0903ba574f61..75b0d3f6e4de 100644
> > --- a/drivers/gpu/drm/bridge/lvds-encoder.c
> > +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> > @@ -13,13 +13,37 @@
> >   
> >   #include <linux/of_graph.h>
> >   
> > +struct lvds_encoder {
> > +	struct drm_bridge bridge;
> > +	struct drm_bridge *panel_bridge;
> > +};
> > +
> > +static int lvds_encoder_attach(struct drm_bridge *bridge)
> > +{
> > +	struct lvds_encoder *lvds_encoder = container_of(bridge,
> > +							 struct lvds_encoder,
> > +							 bridge);
> > +
> > +	return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
> > +				 bridge);
> > +}
> > +
> > +static struct drm_bridge_funcs funcs = {
> > +	.attach = lvds_encoder_attach,
> > +};
> > +
> >   static int lvds_encoder_probe(struct platform_device *pdev)
> >   {
> >   	struct device_node *port;
> >   	struct device_node *endpoint;
> >   	struct device_node *panel_node;
> >   	struct drm_panel *panel;
> > -	struct drm_bridge *bridge;
> > +	struct lvds_encoder *lvds_encoder;
> > +
> > +	lvds_encoder = devm_kzalloc(&pdev->dev, sizeof(*lvds_encoder),
> > +				    GFP_KERNEL);
> > +	if (!lvds_encoder)
> > +		return -ENOMEM;
> >   
> >   	/* Locate the panel DT node. */
> >   	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
> > @@ -49,20 +73,30 @@ static int lvds_encoder_probe(struct platform_device *pdev)
> >   		return -EPROBE_DEFER;
> >   	}
> >   
> > -	bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
> > -	if (IS_ERR(bridge))
> > -		return PTR_ERR(bridge);
> > +	lvds_encoder->panel_bridge =
> > +		devm_drm_panel_bridge_add(&pdev->dev,
> > +					  panel, DRM_MODE_CONNECTOR_LVDS);
> > +	if (IS_ERR(lvds_encoder->panel_bridge))
> > +		return PTR_ERR(lvds_encoder->panel_bridge);
> > +
> > +	/* The panel_bridge bridge is attached to the panel's of_node,
> > +	 * but we need a bridge attached to our of_node for our user
> > +	 * to look up.
> > +	 */
> > +	lvds_encoder->bridge.of_node = pdev->dev.of_node;
> > +	lvds_encoder->bridge.funcs = &funcs;
> > +	drm_bridge_add(&lvds_encoder->bridge);
> >   
> > -	platform_set_drvdata(pdev, bridge);
> > +	platform_set_drvdata(pdev, lvds_encoder);
> >   
> >   	return 0;
> >   }
> >   
> >   static int lvds_encoder_remove(struct platform_device *pdev)
> >   {
> > -	struct drm_bridge *bridge = platform_get_drvdata(pdev);
> > +	struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
> >   
> > -	drm_bridge_remove(bridge);
> > +	drm_bridge_remove(&lvds_encoder->bridge);
> >   
> >   	return 0;
> >   }
> Tested-by: Lothar WaÃmann <LW@xxxxxxxxxxxxxxxxxxx>

queued to drm-misc-fixes.

I think we should send this patch for the stable kernels (v4.12+) too.

Thanks,
Archit

> Lothar WaÃmann

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