From nobody Tue Apr 7 00:45:49 2026 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 420623BC674; Tue, 17 Mar 2026 12:10:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773749401; cv=none; b=QFtgmI28MJfugoyqd3bpjZUxDCQ3oIi8qzQuQhWjJvtZpF2vlAsKD40J1IwkYS+YbeVSupYY2u9JbsawYMvR0WKUmAmZg6upJV8LAthQnhJn/UkwMRhp625lKVmlrldCQCY2weQj23tLEOwmql6GSt1v+LRXvMZxmpDh4yXAngk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773749401; c=relaxed/simple; bh=cWXO8R44lS302LlLp0FBwxZcXLjXHWDn8I6yXfunBBs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rXuXdv3Ow94GDpEgzy89Q6owCqdn3rOlXp3z7xlrDD7cU7JwkQDLFEVzAtuGtoP8YJNFzK0HAczMcx6yNVBPrAf7CZB0ImKUuA5zHzk+GizlQjMJFznV5TSPyefzr1j3v/98d3uJeEDAk8djrgoxiCHeaMMkshs2ZbXz6LJBhWM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=H0U4AvRp; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="H0U4AvRp" Received: from [127.0.1.1] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1A32AC6C; Tue, 17 Mar 2026 13:08:44 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1773749324; bh=cWXO8R44lS302LlLp0FBwxZcXLjXHWDn8I6yXfunBBs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=H0U4AvRpelfkBPuuy1zHgTPQWa2X23wKgHzXeUFOCtycfRqBEBetS0gs1jSvBsjbm 1H6W1IQ73oSwbXO/rTkpOv7YwL+uFJx09kdzT+oHJ7um1U7dtbCOdpaUUBNrqaMO6E x4OC8ngXRleYJq1x2Yry5kiNhk9dvVa4Z5Jnv6q4= From: Tomi Valkeinen Date: Tue, 17 Mar 2026 14:09:42 +0200 Subject: [PATCH v2 3/3] media: subdev: Split v4l2_subdev_get_frame_desc_passthrough() into locked and unlocked Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260317-frame-desc-passthrough-impro-v2-3-0c93b437d85d@ideasonboard.com> References: <20260317-frame-desc-passthrough-impro-v2-0-0c93b437d85d@ideasonboard.com> In-Reply-To: <20260317-frame-desc-passthrough-impro-v2-0-0c93b437d85d@ideasonboard.com> To: Mauro Carvalho Chehab , Sakari Ailus , Laurent Pinchart Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Jai Luthra , Tomi Valkeinen X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=8102; i=tomi.valkeinen+renesas@ideasonboard.com; h=from:subject:message-id; bh=cWXO8R44lS302LlLp0FBwxZcXLjXHWDn8I6yXfunBBs=; b=owEBbQKS/ZANAwAIAfo9qoy8lh71AcsmYgBpuUSRGvmnJGgDzn7WbiYXoE1AiHTYQLsLIkL6F 0RoLvFWKI+JAjMEAAEIAB0WIQTEOAw+ll79gQef86f6PaqMvJYe9QUCablEkQAKCRD6PaqMvJYe 9cP9EACcldRYRHtx3Jdro4a1h89CLNGpjtHGFAjo+Wa7Sab2APDWPTC/E0w4UHhnWWnaQnmrNY+ 7qL8yVrfEZCtzcsBWih9zPD5M+mTCSYhDovQG6eyQVw32xjh8f2Xq0d95wp9mUDUTVugfCQ27RK a3SzPM5cW6AxC2smH0eX/BaourxwEH7vMzx5JW85lmsFQlSO7+R99zPIJYpD08uDPTxajoXIs4X cx0O+CDSnXDQmICxqU94RynkpzTjTLoWwTJQqMFLyqH2SregxtpPvi2c6c0MzALMcyJCJaSQzV+ oAenADPJZeAL+8/5tFGpyO28+UMcN0bPG9tjH9l9S5F4K5UtZZfbUnlZCOidJ9E8vzZgQjfT5/b VcAonvtOpolDZQi2/wuCYLIvFntzYHHDXA3brQZZpMcQbEZ/Op9Ir43rPjb19/pSXJBV32GvZ2l NzF4xCtpFXim8xEm4DOMLZOzL4NqDYt4s3up2rd+hMeuO/mqlaTNG3tDkmrVdMXo8A+/VSP9kVH MMBKayNSUy73LYOPp03xgJBynF4Hh4XK02Nlr11XYMpHb1KHfrgdLoSyLMEqxH17CoG2cBqruFE aoSvDCO2lFrrMlcxC7ezSV1Bi7X7JskLeK58k4GcQK3bWS64AsXu67iTfx3aSeo0/J1RaWvs2Q5 LQ3aiZScGU1msLg== X-Developer-Key: i=tomi.valkeinen+renesas@ideasonboard.com; a=openpgp; fpr=C4380C3E965EFD81079FF3A7FA3DAA8CBC961EF5 The recently added v4l2_subdev_get_frame_desc_passthrough() can be used directly as an implementation for .get_frame_desc subdev op. However, in some cases the drivers may want to add some customizations, while the bulk of the work is still identical to what v4l2_subdev_get_frame_desc_passthrough() does. Current locking scheme makes this impossible to do properly. Split v4l2_subdev_get_frame_desc_passthrough() into two functions: __v4l2_subdev_get_frame_desc_passthrough(), which takes a locked subdev state as a parameter, instead of locking and getting the active state internally. Other than that, it does the same as v4l2_subdev_get_frame_desc_passthrough() used to do. v4l2_subdev_get_frame_desc_passthrough(), which locks the active state and calls __v4l2_subdev_get_frame_desc_passthrough(). In other words, v4l2_subdev_get_frame_desc_passthrough() works as before, but drivers can now alternatively add custom .get_frame_desc code and call v4l2_subdev_get_frame_desc_passthrough(). An example use case is with DS90UB953 serializer: in normal use the serializer passes through everything, but when test-pattern-generator (TPG) is used, an internal TPG source is used. After this commit, the UB953 get_frame_desc() can lock the state, look at the routing table to see if we're in normal or TPG mode, then either call __v4l2_subdev_get_frame_desc_passthrough() if in normal mode, or construct a TPG frame desc if in TPG mode. Signed-off-by: Tomi Valkeinen Reviewed-by: Laurent Pinchart --- drivers/media/v4l2-core/v4l2-subdev.c | 48 ++++++++++++++++++++-----------= ---- include/media/v4l2-subdev.h | 38 +++++++++++++++++++++++---- 2 files changed, 61 insertions(+), 25 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-cor= e/v4l2-subdev.c index 2757378c628a..b73ccd1c83d2 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -2545,21 +2545,21 @@ int v4l2_subdev_s_stream_helper(struct v4l2_subdev = *sd, int enable) } EXPORT_SYMBOL_GPL(v4l2_subdev_s_stream_helper); =20 -int v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd, - unsigned int pad, - struct v4l2_mbus_frame_desc *fd) +int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd, + struct v4l2_subdev_state *state, + unsigned int pad, + struct v4l2_mbus_frame_desc *fd) { struct media_pad *local_sink_pad; struct v4l2_subdev_route *route; - struct v4l2_subdev_state *state; struct device *dev =3D sd->dev; int ret =3D 0; =20 + lockdep_assert_held(state->lock); + if (WARN_ON(!(sd->entity.pads[pad].flags & MEDIA_PAD_FL_SOURCE))) return -EINVAL; =20 - state =3D v4l2_subdev_lock_and_get_active_state(sd); - /* Iterate over sink pads */ media_entity_for_each_pad(&sd->entity, local_sink_pad) { struct v4l2_mbus_frame_desc source_fd; @@ -2586,15 +2586,12 @@ int v4l2_subdev_get_frame_desc_passthrough(struct v= 4l2_subdev *sd, if (!remote_source_pad) { dev_dbg(dev, "Failed to find remote pad for sink pad %u\n", local_sink_pad->index); - ret =3D -EINVAL; - goto out_unlock; + return -EINVAL; } =20 remote_sd =3D media_entity_to_v4l2_subdev(remote_source_pad->entity); - if (!remote_sd) { - ret =3D -EINVAL; - goto out_unlock; - } + if (!remote_sd) + return -EINVAL; =20 ret =3D v4l2_subdev_call(remote_sd, pad, get_frame_desc, @@ -2604,7 +2601,7 @@ int v4l2_subdev_get_frame_desc_passthrough(struct v4l= 2_subdev *sd, dev_err(dev, "Failed to get frame desc from remote subdev %s\n", remote_sd->name); - goto out_unlock; + return ret; } =20 have_source_fd =3D true; @@ -2615,8 +2612,7 @@ int v4l2_subdev_get_frame_desc_passthrough(struct v4l= 2_subdev *sd, dev_err(dev, "Frame desc type mismatch: %u !=3D %u\n", fd->type, source_fd.type); - ret =3D -EPIPE; - goto out_unlock; + return -EPIPE; } } =20 @@ -2631,14 +2627,12 @@ int v4l2_subdev_get_frame_desc_passthrough(struct v= 4l2_subdev *sd, dev_dbg(dev, "Failed to find stream %u from source frame desc\n", route->sink_stream); - ret =3D -EPIPE; - goto out_unlock; + return -EPIPE; } =20 if (fd->num_entries >=3D V4L2_FRAME_DESC_ENTRY_MAX) { dev_dbg(dev, "Frame desc entry limit reached\n"); - ret =3D -ENOSPC; - goto out_unlock; + return -ENOSPC; } =20 fd->entry[fd->num_entries] =3D *source_entry; @@ -2649,7 +2643,21 @@ int v4l2_subdev_get_frame_desc_passthrough(struct v4= l2_subdev *sd, } } =20 -out_unlock: + return 0; +} +EXPORT_SYMBOL_GPL(__v4l2_subdev_get_frame_desc_passthrough); + +int v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd, + unsigned int pad, + struct v4l2_mbus_frame_desc *fd) +{ + struct v4l2_subdev_state *state; + int ret; + + state =3D v4l2_subdev_lock_and_get_active_state(sd); + + ret =3D __v4l2_subdev_get_frame_desc_passthrough(sd, state, pad, fd); + v4l2_subdev_unlock_state(state); =20 return ret; diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 23c03ba7f84c..d256b7ec8f84 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -1723,15 +1723,15 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev = *sd, u32 pad, int v4l2_subdev_s_stream_helper(struct v4l2_subdev *sd, int enable); =20 /** - * v4l2_subdev_get_frame_desc_passthrough() - Helper to implement the subd= ev - * get_frame_desc operation in simple passthrough cases + * __v4l2_subdev_get_frame_desc_passthrough - Helper to implement the + * subdev get_frame_desc operation in simple passthrough cases * @sd: The subdevice + * @state: The locked subdevice active state * @pad: The source pad index * @fd: The mbus frame desc * - * This helper implements get_frame_desc operation for subdevices that pass - * streams through without modification. It can be assigned directly as the - * .get_frame_desc callback in &v4l2_subdev_pad_ops. + * This helper implements the get_frame_desc operation for subdevices that= pass + * streams through without modification. * * The helper iterates over the subdevice's sink pads, calls get_frame_des= c on * the remote subdevice connected to each sink pad, and collects the frame= desc @@ -1744,6 +1744,34 @@ int v4l2_subdev_s_stream_helper(struct v4l2_subdev *= sd, int enable); * sink pads are involved and the upstream sources report different frame = desc * types, -EPIPE is returned. * + * The caller must hold the subdevice's active state lock. This variant is + * intended for drivers that need to perform additional work around the + * passthrough frame descriptor collection. Drivers that do not need any + * customization should use v4l2_subdev_get_frame_desc_passthrough() inste= ad. + * + * Return: 0 on success, or a negative error code otherwise. + */ +int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd, + struct v4l2_subdev_state *state, + unsigned int pad, + struct v4l2_mbus_frame_desc *fd); + +/** + * v4l2_subdev_get_frame_desc_passthrough() - Helper to implement the subd= ev + * get_frame_desc operation in simple passthrough cases + * @sd: The subdevice + * @pad: The source pad index + * @fd: The mbus frame desc + * + * This function locks the subdevice's active state, calls + * __v4l2_subdev_get_frame_desc_passthrough(), and unlocks the state. + * + * This function can be assigned directly as the .get_frame_desc callback = in + * &v4l2_subdev_pad_ops for subdevices that pass streams through without + * modification. Drivers that need to perform additional work should use + * __v4l2_subdev_get_frame_desc_passthrough() in their custom + * .get_frame_desc implementation instead. + * * Return: 0 on success, or a negative error code otherwise. */ int v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd, --=20 2.43.0