drm/nouveau: fix dual-link displays when plugged into single-link outputs

When selecting the native mode for a display we weren't taking into account
whether or not it was actually supported on that particular output.

This patch modifies our native mode selection to run all modes through
mode_valid() first.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index bfa6562..256e82b 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -431,24 +431,27 @@ nouveau_connector_set_property(struct drm_connector *connector,
 }
 
 static struct drm_display_mode *
-nouveau_connector_native_mode(struct nouveau_connector *connector)
+nouveau_connector_native_mode(struct drm_connector *connector)
 {
-       struct drm_device *dev = connector->base.dev;
+       struct drm_connector_helper_funcs *helper = connector->helper_private;
+       struct nouveau_connector *nv_connector = nouveau_connector(connector);
+       struct drm_device *dev = connector->dev;
        struct drm_display_mode *mode, *largest = NULL;
        int high_w = 0, high_h = 0, high_v = 0;
 
-       /* Use preferred mode if there is one.. */
-       list_for_each_entry(mode, &connector->base.probed_modes, head) {
+       list_for_each_entry(mode, &nv_connector->base.probed_modes, head) {
+               if (helper->mode_valid(connector, mode) != MODE_OK)
+                       continue;
+
+               /* Use preferred mode if there is one.. */
                if (mode->type & DRM_MODE_TYPE_PREFERRED) {
                        NV_DEBUG_KMS(dev, "native mode from preferred\n");
                        return drm_mode_duplicate(dev, mode);
                }
-       }
 
-       /* Otherwise, take the resolution with the largest width, then height,
-        * then vertical refresh
-        */
-       list_for_each_entry(mode, &connector->base.probed_modes, head) {
+               /* Otherwise, take the resolution with the largest width, then
+                * height, then vertical refresh
+                */
                if (mode->hdisplay < high_w)
                        continue;
 
@@ -552,7 +555,7 @@ nouveau_connector_get_modes(struct drm_connector *connector)
         */
        if (!nv_connector->native_mode)
                nv_connector->native_mode =
-                       nouveau_connector_native_mode(nv_connector);
+                       nouveau_connector_native_mode(connector);
        if (ret == 0 && nv_connector->native_mode) {
                struct drm_display_mode *mode;
 
@@ -583,9 +586,9 @@ nouveau_connector_mode_valid(struct drm_connector *connector,
 
        switch (nv_encoder->dcb->type) {
        case OUTPUT_LVDS:
-               BUG_ON(!nv_connector->native_mode);
-               if (mode->hdisplay > nv_connector->native_mode->hdisplay ||
-                   mode->vdisplay > nv_connector->native_mode->vdisplay)
+               if (nv_connector->native_mode &&
+                   (mode->hdisplay > nv_connector->native_mode->hdisplay ||
+                    mode->vdisplay > nv_connector->native_mode->vdisplay))
                        return MODE_PANEL;
 
                min_clock = 0;
@@ -727,7 +730,7 @@ nouveau_connector_create_lvds(struct drm_device *dev,
        if (ret == 0)
                goto out;
        nv_connector->detected_encoder = nv_encoder;
-       nv_connector->native_mode = nouveau_connector_native_mode(nv_connector);
+       nv_connector->native_mode = nouveau_connector_native_mode(connector);
        list_for_each_entry_safe(mode, temp, &connector->probed_modes, head)
                drm_mode_remove(connector, mode);