linux-kernel - [PATCH v3 1/3] rpmsg: char: Remove put_device() in rpmsg_eptdev

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Message-Id: <20251113153909.3789-2-dawei.li@linux.dev>
Date: Thu, 13 Nov 2025 23:39:07 +0800
From: Dawei Li <dawei.li@...ux.dev>
To: andersson@...nel.org,
	mathieu.poirier@...aro.org
Cc: linux-remoteproc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	dawei.li@...ux.dev,
	set_pte_at@...look.com,
	stable@...r.kernel.org
Subject: [PATCH v3 1/3] rpmsg: char: Remove put_device() in rpmsg_eptdev_add()

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():

[  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

Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Cc: stable@...r.kernel.org
Signed-off-by: Dawei Li <dawei.li@...ux.dev>
---
 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);
 	kfree(eptdev);
 
 	return ret;
-- 
2.25.1