[PATCH] [STABLE ONLY] firmware: arm_scmi: Fix unused notifier-block in unregister

[PATCH] [STABLE ONLY] firmware: arm_scmi: Fix unused notifier-block in unregister

[Amitai Gottlieb]

In function `scmi_devm_notifier_unregister` the notifier-block parameter
was unused and therefore never passed to `devres_release`. This causes
the function to always return -ENOENT and fail to unregister the
notifier.

In drivers that rely on this function for cleanup this causes
unexpected failures including kernel-panic.

This is not needed upstream becaues the bug was fixed
in a refactor by commit 264a2c520628 ("firmware: arm_scmi: Simplify
scmi_devm_notifier_unregister").  It is needed for the 5.15, 6.1 and
6.6 kernels.

Cc: <stable@vger.kernel.org> # 5.15.x, 6.1.x, and 6.6.x
Fixes: 5ad3d1cf7d34 ("firmware: arm_scmi: Introduce new devres notification ops")
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Amitai Gottlieb <amitaig@hailo.ai>
---

 drivers/firmware/arm_scmi/notify.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index 0efd20cd9d69..4782b115e6ec 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -1539,6 +1539,7 @@ static int scmi_devm_notifier_unregister(struct scmi_device *sdev,
 	dres.handle = sdev->handle;
 	dres.proto_id = proto_id;
 	dres.evt_id = evt_id;
+	dres.nb = nb;
 	if (src_id) {
 		dres.__src_id = *src_id;
 		dres.src_id = &dres.__src_id;
-- 
2.34.1

Re: [PATCH] [STABLE ONLY] firmware: arm_scmi: Fix unused notifier-block in unregister

[Sudeep Holla]

Hi Amitai,

Not sure if you received my earlier reply as I can't find it on the list
and not in sent box as well. But I do see you have cc-ed Greg as requested
but didn't consider other requests, hence the confusion.

Hi Greg,

This is first time I am deal with such an issue which exist only in the
stable tree as the upstream fixed it in some refactoring before the issue
was reported/known. Let us know if this is correct way to add patch to
stable tree only or is there something we are missing or need to take care of.

On Tue, Dec 16, 2025 at 11:00:09AM +0200, Amitai Gottlieb wrote:
> In function `scmi_devm_notifier_unregister` the notifier-block parameter
> was unused and therefore never passed to `devres_release`. This causes
> the function to always return -ENOENT and fail to unregister the
> notifier.
> 
> In drivers that rely on this function for cleanup this causes
> unexpected failures including kernel-panic.
> 
> This is not needed upstream becaues the bug was fixed
> in a refactor by commit 264a2c520628 ("firmware: arm_scmi: Simplify
> scmi_devm_notifier_unregister").  


> It is needed for the 5.15, 6.1 and 6.6 kernels.

I had given you reworded commit message and particularly the above text
to be dropped. It makes no sense to add this say is v5.15 kernel e.g.

> 
> Cc: <stable@vger.kernel.org> # 5.15.x, 6.1.x, and 6.6.x
> Fixes: 5ad3d1cf7d34 ("firmware: arm_scmi: Introduce new devres notification ops")
> Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
> Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>

I had also asked you to add my

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>

-- 
Regards,
Sudeep