1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index bb9ee2c93eca..f2a69cfb6ebf 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -167,6 +167,8 @@ static void omap_disconnect_pipelines(struct drm_device *ddev)
                 pipe->display = NULL;
         }
 
+        memset(&priv->channels, 0, sizeof(priv->channels));
+
         priv->num_pipes = 0;
 }
 
@@ -186,6 +188,7 @@ static int omap_connect_pipelines(struct drm_device *ddev)
 {
         struct omap_drm_private *priv = ddev->dev_private;
         struct omap_dss_device *output = NULL;
+        unsigned int i;
         int r;
 
         if (!omapdss_stack_is_ready())
@@ -218,6 +221,22 @@ static int omap_connect_pipelines(struct drm_device *ddev)
         sort(priv->pipes, priv->num_pipes, sizeof(priv->pipes[0]),
              omap_compare_pipes, NULL);
 
+        /*
+         * Populate the pipeline lookup table by DISPC channel. Only one display
+         * is allowed per channel.
+         */
+        for (i = 0; i < priv->num_pipes; ++i) {
+                struct omap_drm_pipeline *pipe = &priv->pipes[i];
+                enum omap_channel channel = pipe->output->dispc_channel;
+
+                if (WARN_ON(priv->channels[channel] != NULL)) {
+                        r = -EINVAL;
+                        goto cleanup;
+                }
+
+                priv->channels[channel] = pipe;
+        }
+
         return 0;
 
 cleanup: