[{"id":24018,"web_url":"https://patchwork.libcamera.org/comment/24018/","msgid":"<165840215829.1228219.13882800628950639294@Monstersaurus>","date":"2022-07-21T11:15:58","subject":"Re: [libcamera-devel] [RFC PATCH] qcam: Fix IPU3 camera switching","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Kieran Bingham (2022-07-06 10:22:18)\n> On the IPU3 we will disallow acquiring a second camera while one is\n> active. This prevents us from doing a camera switch between the\n> available cameras.\n> \n> Re-instate this facility by ensuring we release the current camera\n> before attempting to acquire the new camera.\n> \n> Signed-off-by: Kieran Bingham \n> ---\n> \n> QCam is broken on IPU3 in that once one camera is running, we can't swap\n> to the other without closing qcam (or swapping to a non IPU3 camera).\n> \n> This seems a bit of a pain - but here's a potential fix.\n> \n> Since writing this patch (some time ago) I know think that trying to\n> reaquire the previous camera if the switch fails might be wrong.\n> \n> I wonder if we should just leave the camera halted, with our 'no-image'\n> logo displayed, and wait. But the only way to 'fix' this would be for\n> the user to choose a new camera, there's no current option to retry\n> acquiring a camera...\n\nDoes anyone have any thoughts or insight on this topic?\n\n\n> src/qcam/main_window.cpp | 26 ++++++++++++++++++++------\n> 1 file changed, 20 insertions(+), 6 deletions(-)\n> \n> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp\n> index 7433d647e8a0..487f522748ca 100644\n> --- a/src/qcam/main_window.cpp\n> +++ b/src/qcam/main_window.cpp\n> @@ -269,11 +269,6 @@ void MainWindow::switchCamera(int index)\n> \n> const std::shared_ptr &cam = cameras[index];\n> \n> - if (cam->acquire()) {\n> - qInfo() << \"Failed to acquire camera\" << cam->id().c_str();\n> - return;\n> - }\n> -\n> qInfo() << \"Switching to camera\" << cam->id().c_str();\n> \n> /*\n> @@ -283,7 +278,26 @@ void MainWindow::switchCamera(int index)\n> startStopAction_->setChecked(false);\n> \n> camera_->release();\n> - camera_ = cam;\n> +\n> + /*\n> + * Only attempt to acquire after releasing to ensure we support\n> + * pipelines which can only stream from one device at a time.\n> + *\n> + * Todo: Consider how we could acquire more than one camera\n> + * but ensure only one could stream at a time.\n> + */\n> + if (cam->acquire()) {\n> + qInfo() << \"Failed to acquire camera\" << cam->id().c_str();\n> + qInfo() << \"Switching back to \" << camera_->id().c_str();\n> +\n> + if (camera_->acquire()) {\n> + qInfo() << \"Failed to reacquire \" << camera_->id().c_str();\n> + return;\n> + }\n> + } else {\n> + /* Acquire was successful, Switch to this camera */\n> + camera_ = cam;\n> + }\n> \n> startStopAction_->setChecked(true);\n> }\n> -- \n> 2.34.1\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 46DD8BE173\n\tfor ;\n\tThu, 21 Jul 2022 11:16:03 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 8830C6330F;\n\tThu, 21 Jul 2022 13:16:02 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0CE95601B8\n\tfor ;\n\tThu, 21 Jul 2022 13:16:01 +0200 (CEST)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 8B364496\n\tfor ;\n\tThu, 21 Jul 2022 13:16:00 +0200 (CEST)"],"DKIM-Signature":["v=1; 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dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"OccoIuf8\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20220706092218.2761216-1-kieran.bingham@ideasonboard.com>","References":"<20220706092218.2761216-1-kieran.bingham@ideasonboard.com>","Cc":"","To":"libcamera devel ","Date":"Thu, 21 Jul 2022 12:15:58 +0100","Message-ID":"<165840215829.1228219.13882800628950639294@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [RFC PATCH] qcam: Fix IPU3 camera switching","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","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":24041,"web_url":"https://patchwork.libcamera.org/comment/24041/","msgid":"","date":"2022-07-21T21:05:02","subject":"Re: [libcamera-devel] [RFC PATCH] qcam: Fix IPU3 camera switching","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Kieran,\n\nThank you for the patch.\n\nOn Wed, Jul 06, 2022 at 10:22:18AM +0100, Kieran Bingham via libcamera-devel wrote:\n> On the IPU3 we will disallow acquiring a second camera while one is\n> active. This prevents us from doing a camera switch between the\n> available cameras.\n> \n> Re-instate this facility by ensuring we release the current camera\n> before attempting to acquire the new camera.\n> \n> Signed-off-by: Kieran Bingham \n> ---\n> \n> QCam is broken on IPU3 in that once one camera is running, we can't swap\n> to the other without closing qcam (or swapping to a non IPU3 camera).\n> \n> This seems a bit of a pain - but here's a potential fix.\n> \n> Since writing this patch (some time ago) I know think that trying to\n> reaquire the previous camera if the switch fails might be wrong.\n> \n> I wonder if we should just leave the camera halted, with our 'no-image'\n> logo displayed, and wait. But the only way to 'fix' this would be for\n> the user to choose a new camera, there's no current option to retry\n> acquiring a camera...\n\nThis looks like a problem on the pipeline handler side, not in qcam. It\nturns out that I have a patch in a branch that has been sitting idle\nthere for way too long, I've posted it ([1]), let's move the discussion\nthere (and it would be nice if you could test it).\n\n[1] https://lists.libcamera.org/pipermail/libcamera-devel/2022-July/032507.html\n\n> src/qcam/main_window.cpp | 26 ++++++++++++++++++++------\n> 1 file changed, 20 insertions(+), 6 deletions(-)\n> \n> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp\n> index 7433d647e8a0..487f522748ca 100644\n> --- a/src/qcam/main_window.cpp\n> +++ b/src/qcam/main_window.cpp\n> @@ -269,11 +269,6 @@ void MainWindow::switchCamera(int index)\n> \n> \tconst std::shared_ptr &cam = cameras[index];\n> \n> -\tif (cam->acquire()) {\n> -\t\tqInfo() << \"Failed to acquire camera\" << cam->id().c_str();\n> -\t\treturn;\n> -\t}\n> -\n> \tqInfo() << \"Switching to camera\" << cam->id().c_str();\n> \n> \t/*\n> @@ -283,7 +278,26 @@ void MainWindow::switchCamera(int index)\n> \tstartStopAction_->setChecked(false);\n> \n> \tcamera_->release();\n> -\tcamera_ = cam;\n> +\n> +\t/*\n> +\t * Only attempt to acquire after releasing to ensure we support\n> +\t * pipelines which can only stream from one device at a time.\n> +\t *\n> +\t * Todo: Consider how we could acquire more than one camera\n> +\t * but ensure only one could stream at a time.\n> +\t */\n> +\tif (cam->acquire()) {\n> +\t\tqInfo() << \"Failed to acquire camera\" << cam->id().c_str();\n> +\t\tqInfo() << \"Switching back to \" << camera_->id().c_str();\n> +\n> +\t\tif (camera_->acquire()) {\n> +\t\t\tqInfo() << \"Failed to reacquire \" << camera_->id().c_str();\n> +\t\t\treturn;\n> +\t\t}\n> +\t} else {\n> +\t\t/* Acquire was successful, Switch to this camera */\n> +\t\tcamera_ = cam;\n> +\t}\n> \n> \tstartStopAction_->setChecked(true);\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 F1D14BD1F1\n\tfor ;\n\tThu, 21 Jul 2022 21:05:05 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A2C846330F;\n\tThu, 21 Jul 2022 23:05:05 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 51874601B8\n\tfor ;\n\tThu, 21 Jul 2022 23:05:04 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id E2D7D496;\n\tThu, 21 Jul 2022 23:05:03 +0200 (CEST)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1658437505;\n\tbh=kPdEOcijQOxROnj0H/T1SL9RVtF6PXczYcTSoYj3YGI=;\n\th=Date:To:References:In-Reply-To:Subject:List-Id:List-Unsubscribe:\n\tList-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:\n\tFrom;\n\tb=nEzi63QkTELif7gFxvUZMG9PA6zIm+IIqcsjRlwF2dn8dG6vFAtJsAlzubUWJVU4x\n\tGOtZPpUVtbIJm2YRJmgcQUizZVRF0cA2meBP9U+fCyvELgPFZCztPmRIdjZ1TanQin\n\tgenNZDFglna1RjuDAlAVgPEB1fN5YpKAA+qqJk/wuohjnTxZjFa20863Y8ALTnvbVO\n\tLcZa2m7sJRdhP3CwHn+eCgq1E5677sPuqJZDEahxfBasDd874lxkBh/7PvZOG+4vYS\n\t1mhpv2QDZoPMg1sjM7DwigRWKH4iUmw6jqIQ46C6Z2A3y6wS8O6Ge30hfQHZIxberG\n\tKPZtp4szSPI3A==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1658437504;\n\tbh=kPdEOcijQOxROnj0H/T1SL9RVtF6PXczYcTSoYj3YGI=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=g57AX9R3ynt7UyJ2faii0uaA5aa5FNVuGPlnhbj4lETKAwZZN9KK7+nQx+K/ZGW3z\n\tZejONmjOeeGi5gzBf+ZUDGaPG+ghxJicqXC+wQ4uVjnzmm3m0o9anOZrGfBkpjAiVd\n\tWFbJRYxXPmj/NuIzg79lq/pwmPs0kp/O33XpHwt0="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"g57AX9R3\"; dkim-atps=neutral","Date":"Fri, 22 Jul 2022 00:05:02 +0300","To":"Kieran Bingham ","Message-ID":"","References":"<20220706092218.2761216-1-kieran.bingham@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20220706092218.2761216-1-kieran.bingham@ideasonboard.com>","Subject":"Re: [libcamera-devel] [RFC PATCH] qcam: Fix IPU3 camera switching","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","From":"Laurent Pinchart via libcamera-devel\n\t","Reply-To":"Laurent Pinchart ","Cc":"libcamera devel ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]