On 11/13/2025 11:39 PM, Dawei Li wrote:
put_device() is called on error path of rpmsg_eptdev_add() to cleanup
resource attached to eptdev->dev, unfortunately it's bogus cause
dev->release() is not set yet.
When a struct device instance is destroyed, driver core framework checks
the possible release() callback from candidates below:
- struct device::release()
- dev->type->release()
- dev->class->dev_release()
Rpmsg eptdev owns none of them so WARN() will complaint the absence of
release():
Hi Dawei,
[ 159.112182] ------------[ cut here ]------------
[ 159.112188] Device '(null)' does not have a release() function, it is broken
and must be fixed. See Documentation/core-api/kobject.rst.
[ 159.112205] WARNING: CPU: 2 PID: 1975 at drivers/base/core.c:2567
device_release+0x7a/0x90
Although my local checkpatch.pl didn’t complain about this log line
exceeding 75 characters, could we simplify it or just provide a summary
instead?
Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Cc: [email protected]
Signed-off-by: Dawei Li <[email protected]>
---
drivers/rpmsg/rpmsg_char.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 34b35ea74aab..1b8297b373f0 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -494,7 +494,6 @@ static int rpmsg_eptdev_add(struct rpmsg_eptdev *eptdev,
if (cdev)
ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
free_eptdev:
- put_device(dev);
Yes, remove put_device can solve the warning issue, however it would
introduce one memleak issue of kobj->name.
https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git/tree/drivers/rpmsg/rpmsg_char.c#n381
dev_set_name(dev, "rpmsg%d", ret); is already called, it depends on
put_device to free memory, right?
kfree(eptdev);
return ret;
--
Thx and BRs,
Zhongqiu Han
