1 files changed, 17 insertions, 3 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index 4f03f74685f0..dccd03726796 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -573,6 +573,8 @@ static const char *channel_names[] = {
 
 void omap_crtc_pre_init(void)
 {
+        memset(omap_crtcs, 0, sizeof(omap_crtcs));
+
         dss_install_mgr_ops(&mgr_ops);
 }
 
@@ -583,18 +585,28 @@ void omap_crtc_pre_uninit(void)
 
 /* initialize crtc */
 struct drm_crtc *omap_crtc_init(struct drm_device *dev,
-                struct drm_plane *plane, enum omap_channel channel, int id)
+                struct drm_plane *plane, struct omap_dss_device *dssdev)
 {
         struct omap_drm_private *priv = dev->dev_private;
         struct drm_crtc *crtc = NULL;
         struct omap_crtc *omap_crtc;
+        enum omap_channel channel;
+        struct omap_dss_device *out;
         int ret;
 
+        out = omapdss_find_output_from_display(dssdev);
+        channel = out->dispc_channel;
+        omap_dss_put_device(out);
+
         DBG("%s", channel_names[channel]);
 
+        /* Multiple displays on same channel is not allowed */
+        if (WARN_ON(omap_crtcs[channel] != NULL))
+                return ERR_PTR(-EINVAL);
+
         omap_crtc = kzalloc(sizeof(*omap_crtc), GFP_KERNEL);
         if (!omap_crtc)
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
         crtc = &omap_crtc->base;
 
@@ -606,8 +618,10 @@ struct drm_crtc *omap_crtc_init(struct drm_device *dev,
         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
                                         &omap_crtc_funcs, NULL);
         if (ret < 0) {
+                dev_err(dev->dev, "%s(): could not init crtc for: %s\n",
+                        __func__, dssdev->name);
                 kfree(omap_crtc);
-                return NULL;
+                return ERR_PTR(ret);
         }
 
         drm_crtc_helper_add(crtc, &omap_crtc_helper_funcs);