[{"id":33903,"web_url":"https://patchwork.libcamera.org/comment/33903/","msgid":"<174366787246.4065590.7805882063805422131@ping.linuxembedded.co.uk>","date":"2025-04-03T08:11:12","subject":"Re: [PATCH v7 3/5] pipeline: simple: Enable frame start events","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Stanislaw Gruszka (2025-04-03 08:45:49)\n> The simple pipeline handler uses frame start events to apply sensor\n> controls through the DelayedControls class. The setSensorControls()\n> function applies the controls directly, which would result in controls\n> being applied twice, if it wasn't for the fact that the pipeline handler\n> forgot to enable the frame start events in the first place. Those two\n> issues cancel each other, but cause controls to always be applied\n> directly.\n> \n> Fix the issue by only applying controls directly in setSensorControls()\n> if no frame start event emitter is available, and by enabling the frame\n> start events in startDevice() otherwise. Disable them in stopDevice()\n> for symmetry.\n> \n> Reviewed-by: Stefan Klug # v6\n> Co-developed-by: Hans de Goede \n> Signed-off-by: Hans de Goede \n> Co-developed-by: Laurent Pinchart \n> Signed-off-by: Laurent Pinchart \n> Signed-off-by: Stanislaw Gruszka \n> ---\n> src/libcamera/pipeline/simple/simple.cpp | 49 +++++++++++++++++++++---\n> 1 file changed, 43 insertions(+), 6 deletions(-)\n> \n> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp\n> index 06e805d89caa..c97904076b63 100644\n> --- a/src/libcamera/pipeline/simple/simple.cpp\n> +++ b/src/libcamera/pipeline/simple/simple.cpp\n> @@ -327,6 +327,7 @@ public:\n> std::list entities_;\n> std::unique_ptr sensor_;\n> V4L2VideoDevice *video_;\n> + V4L2Subdevice *frameStartEmitter_;\n> \n> std::vector configs_;\n> std::map> formats_;\n> @@ -633,6 +634,20 @@ int SimpleCameraData::init()\n> \n> properties_ = sensor_->properties();\n> \n> + /* Find the first subdev that can generate a frame start signal, if any. */\n> + frameStartEmitter_ = nullptr;\n> + for (const Entity &entity : entities_) {\n> + V4L2Subdevice *sd = pipe->subdev(entity.entity);\n> + if (!sd || !sd->supportsFrameStartEvent())\n> + continue;\n> +\n> + LOG(SimplePipeline, Debug)\n> + << \"Using frameStart signal from '\"\n> + << entity.entity->name() << \"'\";\n> + frameStartEmitter_ = sd;\n> + break;\n> + }\n> +\n> return 0;\n> }\n> \n> @@ -983,8 +998,18 @@ void SimpleCameraData::metadataReady(uint32_t frame, const ControlList &metadata\n> void SimpleCameraData::setSensorControls(const ControlList &sensorControls)\n> {\n> delayedCtrls_->push(sensorControls);\n> - ControlList ctrls(sensorControls);\n> - sensor_->setControls(&ctrls);\n> + /*\n> + * Directly apply controls now if there is no frameStart signal.\n\nSmallest nit on whitespace here that I'll fix up when applying.\n\nReviewed-by: Kieran Bingham \n\n\n> + *\n> + * \\todo Applying controls directly not only increases the risk of\n> + * applying them to the wrong frame (or across a frame boundary),\n> + * but it also bypasses delayedCtrls_, creating AGC regulation issues.\n> + * Both problems should be fixed.\n> + */\n> + if (!frameStartEmitter_) {\n> + ControlList ctrls(sensorControls);\n> + sensor_->setControls(&ctrls);\n> + }\n> }\n> \n> /* Retrieve all source pads connected to a sink pad through active routes. */\n> @@ -1409,6 +1434,7 @@ int SimplePipelineHandler::start(Camera *camera, [[maybe_unused]] const ControlL\n> {\n> SimpleCameraData *data = cameraData(camera);\n> V4L2VideoDevice *video = data->video_;\n> + V4L2Subdevice *frameStartEmitter = data->frameStartEmitter_;\n> int ret;\n> \n> const MediaPad *pad = acquirePipeline(data);\n> @@ -1438,8 +1464,15 @@ int SimplePipelineHandler::start(Camera *camera, [[maybe_unused]] const ControlL\n> \n> video->bufferReady.connect(data, &SimpleCameraData::imageBufferReady);\n> \n> - data->video_->frameStart.connect(data->delayedCtrls_.get(),\n> - &DelayedControls::applyControls);\n> + if (frameStartEmitter) {\n> + ret = frameStartEmitter->setFrameStartEnabled(true);\n> + if (ret) {\n> + stop(camera);\n> + return ret;\n> + }\n> + frameStartEmitter->frameStart.connect(data->delayedCtrls_.get(),\n> + &DelayedControls::applyControls);\n> + }\n> \n> ret = video->streamOn();\n> if (ret < 0) {\n> @@ -1472,9 +1505,13 @@ void SimplePipelineHandler::stopDevice(Camera *camera)\n> {\n> SimpleCameraData *data = cameraData(camera);\n> V4L2VideoDevice *video = data->video_;\n> + V4L2Subdevice *frameStartEmitter = data->frameStartEmitter_;\n> \n> - data->video_->frameStart.disconnect(data->delayedCtrls_.get(),\n> - &DelayedControls::applyControls);\n> + if (frameStartEmitter) {\n> + frameStartEmitter->setFrameStartEnabled(false);\n> + frameStartEmitter->frameStart.disconnect(data->delayedCtrls_.get(),\n> + &DelayedControls::applyControls);\n> + }\n> \n> if (data->useConversion_) {\n> if (data->converter_)\n> -- \n> 2.43.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id A342EC3213\n\tfor ;\n\tThu, 3 Apr 2025 08:11:18 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 42DAE6899C;\n\tThu, 3 Apr 2025 10:11:17 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6CC3F68967\n\tfor ;\n\tThu, 3 Apr 2025 10:11:15 +0200 (CEST)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id EBACD105D;\n\tThu, 3 Apr 2025 10:09:21 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"H5xO+/s6\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1743667762;\n\tbh=8tSUehGiuN+9pL56STnnKZ0MHn+Up/cZVHwZCvh5d6I=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=H5xO+/s6B8U4qbMILU3Nqv9izNH66E6mnnj9W+L60ZNcr8tfdeRASaVlYN5u1ubhB\n\tqH9/ZQ9QUw45/ZpmisH3Qu4Y/mvxgdHI6CreH30dtkQycL+WuZjSXyzutH3ydHwfTK\n\tm1FR1ju8Zfyx4h0cYHmIKrdycutDQaMjPGiNmZBs=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20250403074551.263496-4-stanislaw.gruszka@linux.intel.com>","References":"<20250403074551.263496-1-stanislaw.gruszka@linux.intel.com>\n\t<20250403074551.263496-4-stanislaw.gruszka@linux.intel.com>","Subject":"Re: [PATCH v7 3/5] pipeline: simple: Enable frame start events","From":"Kieran Bingham ","Cc":"Milan Zamazal , Hans de Goede ,\n\tLaurent Pinchart ,\n\tSakari Ailus ,\n\tStefan Klug ","To":"Stanislaw Gruszka ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Thu, 03 Apr 2025 09:11:12 +0100","Message-ID":"<174366787246.4065590.7805882063805422131@ping.linuxembedded.co.uk>","User-Agent":"alot/0.10","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]