Introduce a common helper for the pattern of: - allocate new blob property - potentially free old blob property - replace content of indicative property with new blob ID - change member pointer on modeset object
Signed-off-by: Daniel Stone daniels@collabora.com Cc: Dave Airlie airlied@redhat.com --- drivers/gpu/drm/drm_crtc.c | 155 +++++++++++++++++++++++++++++++-------------- 1 file changed, 106 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index aae0d84..ed9341d 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -4237,6 +4237,83 @@ static void drm_property_destroy_blob(struct drm_device *dev, }
/** + * drm_property_replace_global_blob - atomically replace existing blob property + * @dev: drm device + * @replace: location of blob property pointer to be replaced + * @length: length of data for new blob, or 0 for no data + * @data: content for new blob, or NULL for no data + * @obj_holds_id: optional object for property holding blob ID + * @holds_id: optional property holding blob ID + * @return 0 on success or error on failure + * + * This function will atomically replace a global property in the blob list, + * optionally updating a property which holds the ID of that property. It is + * guaranteed to be atomic: no caller will be allowed to see intermediate + * results, and either the entire operation will succeed and clean up the + * previous property, or it will fail and the state will be unchanged. + * + * If length is 0 or data is NULL, no new blob will be created, and the holding + * property, if specified, will be set to 0. + * + * Access to the replace pointer is assumed to be protected by the caller, e.g. + * by holding the relevant modesetting object lock for its parent. + * + * For example, a drm_connector has a 'PATH' property, which contains the ID + * of a blob property with the value of the MST path information. Calling this + * function with replace pointing to the connector's path_blob_ptr, length and + * data set for the new path information, obj_holds_id set to the connector's + * base object, and prop_holds_id set to the path property name, will perform + * a completely atomic update. The access to path_blob_ptr is protected by the + * caller holding a lock on the connector. + */ +static int drm_property_replace_global_blob(struct drm_device *dev, + struct drm_property_blob **replace, + size_t length, + const void *data, + struct drm_mode_object *obj_holds_id, + struct drm_property *prop_holds_id) +{ + struct drm_property_blob *new_blob = NULL; + struct drm_property_blob *old_blob = NULL; + int ret; + + WARN_ON(replace == NULL); + + old_blob = *replace; + + if (length && data) { + new_blob = drm_property_create_blob(dev, length, data); + if (!new_blob) + return -EINVAL; + } + + /* This does not need to be synchronised with blob_lock, as the + * get_properties ioctl locks all modesetting objects, and + * obj_holds_id must be locked before calling here, so we cannot + * have its value out of sync with the list membership modified + * below under blob_lock. */ + if (obj_holds_id) { + ret = drm_object_property_set_value(obj_holds_id, + prop_holds_id, + new_blob ? + new_blob->base.id : 0); + if (ret != 0) + goto err_created; + } + + if (old_blob) + drm_property_destroy_blob(dev, old_blob); + + *replace = new_blob; + + return 0; + +err_created: + drm_property_destroy_blob(dev, new_blob); + return ret; +} + +/** * drm_mode_getblob_ioctl - get the contents of a blob property value * @dev: DRM device * @data: ioctl data @@ -4285,7 +4362,7 @@ done: /** * drm_mode_connector_set_path_property - set tile property on connector * @connector: connector to set property on. - * @path: path to use for property. + * @path: path to use for property; must not be NULL. * * This creates a property to expose to userspace to specify a * connector path. This is mainly used for DisplayPort MST where @@ -4299,20 +4376,14 @@ int drm_mode_connector_set_path_property(struct drm_connector *connector, const char *path) { struct drm_device *dev = connector->dev; - size_t size = strlen(path) + 1; int ret;
- if (connector->path_blob_ptr) - drm_property_destroy_blob(dev, connector->path_blob_ptr); - - connector->path_blob_ptr = drm_property_create_blob(connector->dev, - size, path); - if (!connector->path_blob_ptr) - return -EINVAL; - - ret = drm_object_property_set_value(&connector->base, - dev->mode_config.path_property, - connector->path_blob_ptr->base.id); + ret = drm_property_replace_global_blob(dev, + &connector->path_blob_ptr, + strlen(path) + 1, + path, + &connector->base, + dev->mode_config.path_property); return ret; } EXPORT_SYMBOL(drm_mode_connector_set_path_property); @@ -4331,16 +4402,16 @@ EXPORT_SYMBOL(drm_mode_connector_set_path_property); int drm_mode_connector_set_tile_property(struct drm_connector *connector) { struct drm_device *dev = connector->dev; - int ret, size; char tile[256]; - - if (connector->tile_blob_ptr) - drm_property_destroy_blob(dev, connector->tile_blob_ptr); + int ret;
if (!connector->has_tile) { - connector->tile_blob_ptr = NULL; - ret = drm_object_property_set_value(&connector->base, - dev->mode_config.tile_property, 0); + ret = drm_property_replace_global_blob(dev, + &connector->tile_blob_ptr, + 0, + NULL, + &connector->base, + dev->mode_config.tile_property); return ret; }
@@ -4349,16 +4420,13 @@ int drm_mode_connector_set_tile_property(struct drm_connector *connector) connector->num_h_tile, connector->num_v_tile, connector->tile_h_loc, connector->tile_v_loc, connector->tile_h_size, connector->tile_v_size); - size = strlen(tile) + 1;
- connector->tile_blob_ptr = drm_property_create_blob(connector->dev, - size, tile); - if (!connector->tile_blob_ptr) - return -EINVAL; - - ret = drm_object_property_set_value(&connector->base, - dev->mode_config.tile_property, - connector->tile_blob_ptr->base.id); + ret = drm_property_replace_global_blob(dev, + &connector->tile_blob_ptr, + strlen(tile) + 1, + tile, + &connector->base, + dev->mode_config.tile_property); return ret; } EXPORT_SYMBOL(drm_mode_connector_set_tile_property); @@ -4378,33 +4446,22 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector, const struct edid *edid) { struct drm_device *dev = connector->dev; - size_t size; + size_t size = 0; int ret;
/* ignore requests to set edid when overridden */ if (connector->override_edid) return 0;
- if (connector->edid_blob_ptr) - drm_property_destroy_blob(dev, connector->edid_blob_ptr); - - /* Delete edid, when there is none. */ - if (!edid) { - connector->edid_blob_ptr = NULL; - ret = drm_object_property_set_value(&connector->base, dev->mode_config.edid_property, 0); - return ret; - } - - size = EDID_LENGTH * (1 + edid->extensions); - connector->edid_blob_ptr = drm_property_create_blob(connector->dev, - size, edid); - if (!connector->edid_blob_ptr) - return -EINVAL; - - ret = drm_object_property_set_value(&connector->base, - dev->mode_config.edid_property, - connector->edid_blob_ptr->base.id); + if (edid) + size = EDID_LENGTH + (1 + edid->extensions);
+ ret = drm_property_replace_global_blob(dev, + &connector->edid_blob_ptr, + size, + edid, + &connector->base, + dev->mode_config.edid_property); return ret; } EXPORT_SYMBOL(drm_mode_connector_update_edid_property);