Message-ID: <sashiko-outbox-198683@kernel.org>
From: sashiko-bot@kernel.org
Subject: Re: [PATCHv3 10/13] media: uapi: cec.h: add
 CEC_EVENT_FL_STATE_HPD_PRESENT flag
To: "Hans Verkuil" <hverkuil+cisco@kernel.org>
Cc: dri-devel@lists.freedesktop.org, media-ci@linuxtv.org
In-Reply-To: <81a832c5568748e37f081d217998f80880ab8dc4.1793863347.git.hverkuil+cisco@kernel.org>
References: <cover.1793863347.git.hverkuil+cisco@kernel.org>
 <81a832c5568748e37f081d217998f80880ab8dc4.1793863347.git.hverkuil+cisco@kernel.org>
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Date: Thu, 05 Nov 2026 07:35:42 +0000
Precedence: list
Reply-To: sashiko-reviews@lists.linux.dev
Sender: "dri-devel" <dri-devel-bounces@lists.freedesktop.org>

Thank you for your contribution! Sashiko AI review found 1 potential issue(=
s) to consider:
- [Medium] media: cec: unimplemented and undocumented CEC_EVENT_FL_STATE_HP=
D_PRESENT flag
--

commit 6f18f1544823dafcf8a17b474c711348256f2340
Author: Hans Verkuil <hverkuil+cisco@kernel.org>

media: uapi: cec.h: add CEC_EVENT_FL_STATE_HPD_PRESENT flag

This commit adds the CEC_EVENT_FL_STATE_HPD_PRESENT flag to
include/uapi/linux/cec.h to report whether HPD is present.

> diff --git a/include/uapi/linux/cec.h b/include/uapi/linux/cec.h
> index fdfc97a6e4ec0..d9300a6010806 100644
> --- a/include/uapi/linux/cec.h
> +++ b/include/uapi/linux/cec.h
> @@ -453,6 +453,7 @@ struct cec_connector_info {
> =20
>  #define CEC_EVENT_FL_INITIAL_STATE	(1 << 0)
>  #define CEC_EVENT_FL_DROPPED_EVENTS	(1 << 1)
> +#define CEC_EVENT_FL_STATE_HPD_PRESENT	(1 << 2)

[Severity: Medium]
The commit message states that CEC_EVENT_FL_STATE_HPD_PRESENT will report
whether HPD is present or not, but nothing in the kernel ever sets or
references this flag.

When userspace dequeues CEC_EVENT_STATE_CHANGE events via CEC_DQEVENT, the
events are populated in cec_post_state_event() in
drivers/media/cec/core/cec-adap.c:

	struct cec_event ev =3D {
		.event =3D CEC_EVENT_STATE_CHANGE,
	};

and on device open in cec_open() in drivers/media/cec/core/cec-api.c:

	struct cec_event ev =3D {
		.event =3D CEC_EVENT_STATE_CHANGE,
		.flags =3D CEC_EVENT_FL_INITIAL_STATE,
	};

Neither path sets CEC_EVENT_FL_STATE_HPD_PRESENT in ev.flags, so any
application checking ev.flags & CEC_EVENT_FL_STATE_HPD_PRESENT will always
observe 0.

In addition, Documentation/userspace-api/media/cec/cec-ioc-dqevent.rst
(under the CEC Event Flags table) and include/uapi/linux/cec.h do not
document CEC_EVENT_FL_STATE_HPD_PRESENT or specify which CEC_EVENT_* types
carry it.

Finally, without a corresponding capability flag or tri-state indicator
(unlike struct cec_event_state_change.have_conn_info, which is gated by
CEC_CAP_CONNECTOR_INFO), how can userspace distinguish between HPD being
low, a CEC driver that does not report HPD state, and an older kernel that
predates CEC_EVENT_FL_STATE_HPD_PRESENT? Should this UAPI definition be
held back until an in-kernel user, documentation, and capability signaling
are included?

--=20
Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/81a832c5568748e37f0=
81d217998f80880ab8dc4.1793863347.git.hverkuil+cisco@kernel.org?part=3D1