drm/omap: Don't call EDID read operation recursively

Instead of calling the EDID read operation (.read_edid()) recursively
from the display device back to the first device that provides EDID read
support, iterate over the devices manually in the DRM connector code.
This moves the complexity to a single central location and simplifies
the logic in omap_dss_device drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 58 insertions, 43 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
index 344414ef3962..5091991363d6 100644
--- a/drivers/gpu/drm/omapdrm/omap_connector.c
+++ b/drivers/gpu/drm/omapdrm/omap_connector.c
@@ -170,65 +170,80 @@ static void omap_connector_destroy(struct drm_connector *connector)
 
 #define MAX_EDID  512
 
+static int omap_connector_get_modes_edid(struct drm_connector *connector,
+                                         struct omap_dss_device *dssdev)
+{
+        struct omap_connector *omap_connector = to_omap_connector(connector);
+        enum drm_connector_status status;
+        void *edid;
+        int n;
+
+        status = omap_connector_detect(connector, false);
+        if (status != connector_status_connected)
+                goto no_edid;
+
+        edid = kzalloc(MAX_EDID, GFP_KERNEL);
+        if (!edid)
+                goto no_edid;
+
+        if (dssdev->ops->read_edid(dssdev, edid, MAX_EDID) <= 0 ||
+            !drm_edid_is_valid(edid)) {
+                kfree(edid);
+                goto no_edid;
+        }
+
+        drm_connector_update_edid_property(connector, edid);
+        n = drm_add_edid_modes(connector, edid);
+
+        omap_connector->hdmi_mode = drm_detect_hdmi_monitor(edid);
+
+        kfree(edid);
+        return n;
+
+no_edid:
+        drm_connector_update_edid_property(connector, NULL);
+        return 0;
+}
+
 static int omap_connector_get_modes(struct drm_connector *connector)
 {
         struct omap_connector *omap_connector = to_omap_connector(connector);
-        struct omap_dss_device *dssdev = omap_connector->dssdev;
-        struct drm_device *dev = connector->dev;
-        int n = 0;
+        struct omap_dss_device *dssdev;
+        struct drm_display_mode *mode;
+        struct videomode vm = {0};
 
         DBG("%s", omap_connector->dssdev->name);
 
-        /* if display exposes EDID, then we parse that in the normal way to
-         * build table of supported modes.. otherwise (ie. fixed resolution
+        /*
+         * If display exposes EDID, then we parse that in the normal way to
+         * build table of supported modes. Otherwise (ie. fixed resolution
          * LCD panels) we just return a single mode corresponding to the
-         * currently configured timings:
+         * currently configured timings.
          */
-        if (dssdev->ops->read_edid) {
-                void *edid = kzalloc(MAX_EDID, GFP_KERNEL);
-
-                if (!edid)
-                        return 0;
-
-                if ((dssdev->ops->read_edid(dssdev, edid, MAX_EDID) > 0) &&
-                                drm_edid_is_valid(edid)) {
-                        drm_connector_update_edid_property(
-                                        connector, edid);
-                        n = drm_add_edid_modes(connector, edid);
-
-                        omap_connector->hdmi_mode =
-                                drm_detect_hdmi_monitor(edid);
-                } else {
-                        drm_connector_update_edid_property(
-                                        connector, NULL);
-                }
-
-                kfree(edid);
-        } else {
-                struct drm_display_mode *mode = drm_mode_create(dev);
-                struct videomode vm = {0};
+        dssdev = omap_connector_find_device(connector,
+                                            OMAP_DSS_DEVICE_OP_EDID);
+        if (dssdev)
+                return omap_connector_get_modes_edid(connector, dssdev);
 
-                if (!mode)
-                        return 0;
+        mode = drm_mode_create(connector->dev);
+        if (!mode)
+                return 0;
 
-                dssdev->ops->get_timings(dssdev, &vm);
+        dssdev = omap_connector->dssdev;
+        dssdev->ops->get_timings(dssdev, &vm);
 
-                drm_display_mode_from_videomode(&vm, mode);
+        drm_display_mode_from_videomode(&vm, mode);
 
-                mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
-                drm_mode_set_name(mode);
-                drm_mode_probed_add(connector, mode);
+        mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+        drm_mode_set_name(mode);
+        drm_mode_probed_add(connector, mode);
 
-                if (dssdev->driver && dssdev->driver->get_size) {
-                        dssdev->driver->get_size(dssdev,
+        if (dssdev->driver && dssdev->driver->get_size)
+                dssdev->driver->get_size(dssdev,
                                          &connector->display_info.width_mm,
                                          &connector->display_info.height_mm);
-                }
 
-                n = 1;
-        }
-
-        return n;
+        return 1;
 }
 
 static int omap_connector_mode_valid(struct drm_connector *connector,