[RFC PATCH 1/2] drm: store connector name in connector struct

[Jani Nikula]

This makes drm_get_connector_name() thread safe.

Reference: http://lkml.kernel.org/r/645ee6e22cad47d38a2b35c21c8d5fe3 at 
DC1-MBX-01.ptsecurity.ru
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/drm_crtc.c | 36 ++++++++++++++++++++----------------
 include/drm/drm_crtc.h     |  2 ++
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 461d19bd14ee..5781130b4126 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -277,21 +277,11 @@ EXPORT_SYMBOL(drm_get_encoder_name);

 /**
  * drm_get_connector_name - return a string for connector
- * @connector: connector to compute name of
- *
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
+ * @connector: the connector to get name for
  */
 const char *drm_get_connector_name(const struct drm_connector *connector)
 {
-       static char buf[32];
-
-       snprintf(buf, 32, "%s-%d",
-                drm_connector_enum_list[connector->connector_type].name,
-                connector->connector_type_id);
-       return buf;
+       return connector->name;
 }
 EXPORT_SYMBOL(drm_get_connector_name);

@@ -824,7 +814,7 @@ int drm_connector_init(struct drm_device *dev,

        ret = drm_mode_object_get(dev, &connector->base, 
DRM_MODE_OBJECT_CONNECTOR);
        if (ret)
-               goto out;
+               goto out_unlock;

        connector->base.properties = &connector->properties;
        connector->dev = dev;
@@ -834,9 +824,17 @@ int drm_connector_init(struct drm_device *dev,
                ida_simple_get(connector_ida, 1, 0, GFP_KERNEL);
        if (connector->connector_type_id < 0) {
                ret = connector->connector_type_id;
-               drm_mode_object_put(dev, &connector->base);
-               goto out;
+               goto out_out;
        }
+       connector->name =
+               kasprintf(GFP_KERNEL, "%s-%d",
+                         drm_connector_enum_list[connector_type].name,
+                         connector->connector_type_id);
+       if (!connector->name) {
+               ret = -ENOMEM;
+               goto out_put;
+       }
+
        INIT_LIST_HEAD(&connector->probed_modes);
        INIT_LIST_HEAD(&connector->modes);
        connector->edid_blob_ptr = NULL;
@@ -853,7 +851,11 @@ int drm_connector_init(struct drm_device *dev,
        drm_object_attach_property(&connector->base,
                                      dev->mode_config.dpms_property, 0);

- out:
+out_put:
+       if (ret)
+               drm_mode_object_put(dev, &connector->base);
+
+out_unlock:
        drm_modeset_unlock_all(dev);

        return ret;
@@ -881,6 +883,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
                   connector->connector_type_id);

        drm_mode_object_put(dev, &connector->base);
+       kfree(connector->name);
+       connector->name = NULL;
        list_del(&connector->head);
        dev->mode_config.num_connector--;
 }
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index c061bb372199..d4cd7e513280 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -444,6 +444,7 @@ struct drm_encoder {
  * @attr: sysfs attributes
  * @head: list management
  * @base: base KMS object
+ * @name: connector name
  * @connector_type: one of the %DRM_MODE_CONNECTOR_<foo> types from drm_mode.h
  * @connector_type_id: index into connector type enum
  * @interlace_allowed: can this connector handle interlaced modes?
@@ -482,6 +483,7 @@ struct drm_connector {

        struct drm_mode_object base;

+       char *name;
        int connector_type;
        int connector_type_id;
        bool interlace_allowed;
-- 
1.9.1