[PATCH v6 07/10] drm/bridge_connector: hook drm_atomic_helper_connector_hdmi_hotplug_edid()

[Dmitry Baryshkov]

Extend drm_bridge_connector code to read the EDID and use it to update
connector status if the bridge chain implements HDMI bridge. Performing
it from the generic location minimizes individual bridge's code and
enforces standard behaviour from all corresponding drivers.

Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
---
 drivers/gpu/drm/display/drm_bridge_connector.c | 27 ++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c 
b/drivers/gpu/drm/display/drm_bridge_connector.c
index 
4fa1bb73d430d02d5b79a1a184c203ec9e9c66e7..0ff82900bd07933e292948446b9637ebf2076694
 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -17,6 +17,7 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/display/drm_hdmi_helper.h>
 #include <drm/display/drm_hdmi_state_helper.h>
@@ -182,11 +183,29 @@ drm_bridge_connector_detect(struct drm_connector 
*connector, bool force)
        struct drm_bridge_connector *bridge_connector =
                to_drm_bridge_connector(connector);
        struct drm_bridge *detect = bridge_connector->bridge_detect;
+       struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
        enum drm_connector_status status;
 
        if (detect) {
                status = detect->funcs->detect(detect);
 
+               if (hdmi) {
+                       const struct drm_edid *drm_edid;
+                       struct drm_bridge *bridge;
+                       int ret;
+
+                       bridge = bridge_connector->bridge_edid;
+                       if (!bridge)
+                               return status;
+
+                       drm_edid = drm_bridge_edid_read(bridge, connector);
+                       ret = 
drm_atomic_helper_connector_hdmi_hotplug_edid(connector, status, drm_edid);
+                       if (ret)
+                               drm_warn(connector->dev, "updating EDID failed 
with %d\n", ret);
+
+                       drm_edid_free(drm_edid);
+               }
+
                drm_bridge_connector_hpd_notify(connector, status);
        } else {
                switch (connector->connector_type) {
@@ -278,6 +297,14 @@ static int drm_bridge_connector_get_modes(struct 
drm_connector *connector)
                to_drm_bridge_connector(connector);
        struct drm_bridge *bridge;
 
+       /*
+        * If there is a HDMI bridge, EDID has been updated as a part of
+        * the .detect(). Just update the modes here.
+        */
+       bridge = bridge_connector->bridge_hdmi;
+       if (bridge)
+               return drm_edid_connector_add_modes(connector);
+
        /*
         * If display exposes EDID, then we parse that in the normal way to
         * build table of supported modes.

-- 
2.39.5