drm/atmel-hlcdc: Fix output initialization

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@free-electrons.com>
Fixes: ffec6c22a980 ("drm: convert drivers to use drm_of_find_panel_or_bridge")
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1495110921-4032-1-git-send-email-boris.brezillon@free-electrons.com

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
index 65a3bd7a0c00dbf919d46e6d464d8bce8a5ccfd1..423dda2785d44fd2a900a406d7b1d86c3269d970 100644 (file)
--- 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 @@ err_encoder_cleanup:
 
 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;
 }