drm: make mode_valid callback optional

Many drm connectors do not need mode validation.
The patch makes this callback optional and removes dumb implementations.

v2: Rebase:
- imx move to a shared (but still dummy) ->mode_valid implementation.
- probe helpers have been extracted to drm_probe_helper.c

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index e70f54d4a581..d06340985a72 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -169,7 +169,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
         drm_mode_validate_flag(connector, mode_flags);
 
         list_for_each_entry(mode, &connector->modes, head) {
-                if (mode->status == MODE_OK)
+                if (mode->status == MODE_OK && connector_funcs->mode_valid)
                         mode->status = connector_funcs->mode_valid(connector,
                                                                    mode);
         }