[PATCH v3 06/13] coresight: Fix loss of connection info when a module is unloaded

From: James Clark
Date: Wed Mar 29 2023 - 07:54:47 EST


child_fwnode should be a read only property based on the DT. If it's
cleared on the parent device when a child is unloaded, then when the
child is loaded again the connection won't be remade.

child_dev should be cleared instead which signifies that the connection
should be remade when the child_fwnode registers a new coresight_device.

Similarly the reference count shouldn't be decremented as long as the
parent device exists. The correct place to drop the reference is in
coresight_release_platform_data() which is already done.

Signed-off-by: James Clark <james.clark@xxxxxxx>
---
drivers/hwtracing/coresight/coresight-core.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index bfe1b93aca4e..12cbb68e8e1c 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1414,13 +1414,8 @@ static int coresight_remove_match(struct device *dev, void *data)
if (csdev->dev.fwnode == conn->dest_fwnode) {
iterator->orphan = true;
coresight_remove_links(iterator, conn);
- /*
- * Drop the reference to the handle for the remote
- * device acquired in parsing the connections from
- * platform data.
- */
- fwnode_handle_put(conn->dest_fwnode);
- conn->dest_fwnode = NULL;
+
+ conn->dest_dev = NULL;
/* No need to continue */
break;
}
@@ -1553,7 +1548,6 @@ void coresight_release_platform_data(struct coresight_device *csdev,
* is going away
*/
fwnode_handle_put(conns[i].dest_fwnode);
- pdata->out_conns[i].dest_fwnode = NULL;
}
if (csdev)
coresight_remove_conns_sysfs_group(csdev);
--
2.34.1