[PATCH v2 3/4] drm/modes: Add a function to clear preferred modes

[Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>]

Add a function to clear the preferred bit of a connector's existing modes.
This is useful for edp panel to unset the preferred modes read from edid
if the panel has hard-coded modes.

Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
v1->v2:
- fix doc string (reported by kernel test robot).
- split mode and panel patches.
---
 drivers/gpu/drm/drm_modes.c | 16 ++++++++++++++++
 include/drm/drm_modes.h     |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index ac9a406250c5..be3e9e931219 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1933,6 +1933,22 @@ void drm_connector_list_update(struct drm_connector *connector)
 }
 EXPORT_SYMBOL(drm_connector_list_update);
 
+/**
+ * drm_mode_unset_preferred_modes - clear the preferred bit on existing modes.
+ * @connector: the connector to update
+ *
+ * Walk the mode list for connector, clearing the preferred status on existing
+ * modes.
+ */
+void drm_mode_unset_preferred_modes(struct drm_connector *connector)
+{
+	struct drm_display_mode *cur_mode;
+
+	list_for_each_entry(cur_mode, &connector->probed_modes, head)
+		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
+}
+EXPORT_SYMBOL_GPL(drm_mode_unset_preferred_modes);
+
 static int drm_mode_parse_cmdline_bpp(const char *str, char **end_ptr,
 				      struct drm_cmdline_mode *mode)
 {
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index c613f0abe9dc..301817e00a15 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -560,6 +560,7 @@ void drm_mode_prune_invalid(struct drm_device *dev,
 			    struct list_head *mode_list, bool verbose);
 void drm_mode_sort(struct list_head *mode_list);
 void drm_connector_list_update(struct drm_connector *connector);
+void drm_mode_unset_preferred_modes(struct drm_connector *connector);
 
 /* parsing cmdline modes */
 bool
-- 
2.42.0.869.gea05f2083d-goog