[RFC][PATCH 05/11] drm/edid: Clear display info fully

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Now that we have split the display info into static and dynamic parts,
we can just zero out the entire dynamic part with memset(). Previously
we were just clearing parts of it, leaving stale data in other parts
(eg. HDMI SCDC capabilities).

Also when the edid is NULL drm_add_edid_modes() bails out early skipping
the call to drm_add_display_info(). Thus we would again leave stale
data behind. To avoid that let's clear out the display info at the
very start of drm_add_edid_modes().

Cc: Keith Packard <keithp at keithp.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_connector.c |  3 +--
 drivers/gpu/drm/drm_edid.c      | 23 +++--------------------
 2 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index d73e97ed7dff..ddd7d978f462 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1389,10 +1389,9 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 	 * duplicate it rather than attempt to ensure some arbitrary
 	 * ordering of calls.
 	 */
+	drm_reset_display_info(connector);
 	if (edid)
 		drm_add_display_info(connector, edid);
-	else
-		drm_reset_display_info(connector);
 
 	drm_object_property_set_value(&connector->base,
 				      dev->mode_config.non_desktop_property,
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 788fee4b4bf9..78c1f37be3db 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4443,37 +4443,18 @@ drm_reset_display_info(struct drm_connector *connector)
 {
 	struct drm_display_info *info = &connector->display_info;
 
-	info->width_mm = 0;
-	info->height_mm = 0;
-
-	info->bpc = 0;
-	info->color_formats = 0;
-	info->cea_rev = 0;
-	info->max_tmds_clock = 0;
-	info->dvi_dual = false;
-	info->has_hdmi_infoframe = false;
-
-	info->non_desktop = 0;
+	memset(info, 0, sizeof(*info));
 }
 EXPORT_SYMBOL_GPL(drm_reset_display_info);
 
 u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid)
 {
 	struct drm_display_info *info = &connector->display_info;
-
 	u32 quirks = edid_get_quirks(edid);
 
 	info->width_mm = edid->width_cm * 10;
 	info->height_mm = edid->height_cm * 10;
 
-	/* driver figures it out in this case */
-	info->bpc = 0;
-	info->color_formats = 0;
-	info->cea_rev = 0;
-	info->max_tmds_clock = 0;
-	info->dvi_dual = false;
-	info->has_hdmi_infoframe = false;
-
 	info->non_desktop = !!(quirks & EDID_QUIRK_NON_DESKTOP);
 
 	DRM_DEBUG_KMS("non_desktop set to %d\n", info->non_desktop);
@@ -4684,6 +4665,8 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
 	int num_modes = 0;
 	u32 quirks;
 
+	drm_reset_display_info(connector);
+
 	if (edid == NULL) {
 		clear_eld(connector);
 		return 0;
-- 
2.13.6