On 02/04/2025 12:00 pm, Dan Carpenter wrote:

Hello James Clark,

Commit 3d4ff657e454 ("coresight: Dynamically add connections") from Apr 25, 2023 (linux-next), leads to the following Smatch static checker warning:

drivers/hwtracing/coresight/coresight-platform.c:279 of_coresight_parse_endpoint() warn: inconsistent refcounting 'rep->kobj.kref.refcount.refs.counter':

drivers/hwtracing/coresight/coresight-platform.c 196 static int of_coresight_parse_endpoint(struct device *dev, 197 struct device_node *ep, 198 struct coresight_platform_data *pdata) 199 { 200 int ret = 0; 201 struct of_endpoint endpoint, rendpoint; 202 struct device_node *rparent = NULL; 203 struct device_node *rep = NULL; 204 struct device *rdev = NULL; 205 struct fwnode_handle *rdev_fwnode; 206 struct coresight_connection conn = {}; 207 struct coresight_connection *new_conn; 208 209 do { 210 /* Parse the local port details */ 211 if (of_graph_parse_endpoint(ep, &endpoint)) 212 break; 213 /* 214 * Get a handle on the remote endpoint and the device it is 215 * attached to. 216 */ 217 rep = of_graph_get_remote_endpoint(ep); 218 if (!rep) 219 break; 220 rparent = of_coresight_get_port_parent(rep); 221 if (!rparent) 222 break; 223 if (of_graph_parse_endpoint(rep, &rendpoint)) 224 break; 225 226 rdev_fwnode = of_fwnode_handle(rparent); 227 /* If the remote device is not available, defer probing */ 228 rdev = coresight_find_device_by_fwnode(rdev_fwnode); 229 if (!rdev) { 230 ret = -EPROBE_DEFER; 231 break; 232 } 233 234 conn.src_port = endpoint.port; 235 /* 236 * Hold the refcount to the target device. This could be 237 * released via: 238 * 1) coresight_release_platform_data() if the probe fails or 239 * this device is unregistered. 240 * 2) While removing the target device via 241 * coresight_remove_match() 242 */ 243 conn.dest_fwnode = fwnode_handle_get(rdev_fwnode); 244 conn.dest_port = rendpoint.port; 245 246 /* 247 * Get the firmware node of the filter source through the 248 * reference. This could be used to filter the source in 249 * building path. 250 */ 251 conn.filter_src_fwnode = 252 fwnode_find_reference(&ep->fwnode, "filter-source", 0); 253 if (IS_ERR(conn.filter_src_fwnode)) { 254 conn.filter_src_fwnode = NULL; 255 } else { 256 conn.filter_src_dev = 257 coresight_find_csdev_by_fwnode(conn.filter_src_fwnode); 258 if (conn.filter_src_dev && 259 !coresight_is_device_source(conn.filter_src_dev)) { 260 dev_warn(dev, "port %d: Filter handle is not a trace source : %s\n", 261 conn.src_port, dev_name(&conn.filter_src_dev->dev)); 262 conn.filter_src_dev = NULL; 263 conn.filter_src_fwnode = NULL; 264 } 265 } 266 267 new_conn = coresight_add_out_conn(dev, pdata, &conn); 268 if (IS_ERR_VALUE(new_conn)) { 269 fwnode_handle_put(conn.dest_fwnode); 270 return PTR_ERR(new_conn);

Should this be a break statement instead of return statement?

Hi Dan,

Yes it probably should, I'll send a patch.

Thanks James