{"id":17897,"url":"https://patchwork.libcamera.org/api/patches/17897/?format=json","web_url":"https://patchwork.libcamera.org/patch/17897/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20221124144553.3012369-1-kieran.bingham@ideasonboard.com>","date":"2022-11-24T14:45:53","name":"[libcamera-devel,v5] libcamera: v4l2_device: Workaround faulty control menus","commit_ref":"96ed45b9711e5c70afc4f91eab0ed657ccfb9695","pull_url":null,"state":"accepted","archived":false,"hash":"12c1a58dbbaf19021373ba119be7b1e736b3f92c","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/?format=json","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/17897/mbox/","series":[{"id":3640,"url":"https://patchwork.libcamera.org/api/series/3640/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=3640","date":"2022-11-24T14:45:53","name":"[libcamera-devel,v5] libcamera: v4l2_device: Workaround faulty control menus","version":5,"mbox":"https://patchwork.libcamera.org/series/3640/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/17897/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/17897/checks/","tags":{},"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 33711BDE6B\n\tfor ;\n\tThu, 24 Nov 2022 14:45:59 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 7DAFE6331F;\n\tThu, 24 Nov 2022 15:45:58 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 8C8CF6330D\n\tfor ;\n\tThu, 24 Nov 2022 15:45:57 +0100 (CET)","from Monstersaurus.local\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 DCC52496;\n\tThu, 24 Nov 2022 15:45:56 +0100 (CET)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1669301158;\n\tbh=k1m8QQ1vKRcT8Yf95deLGhvehL5TdbzwSo0aCazGe8Y=;\n\th=To:Date:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post:\n\tList-Help:List-Subscribe:From:Reply-To:Cc:From;\n\tb=C/9e7ddWUx821dvkotVSlyLWj/xuvV+TOz0LGBJIk9+wcozQgw7tNv3y/gIUUhN6W\n\t1LM92gWCRcaUPgOmNohfLWlk954GAdvLFOrQXAJGHxBzT31tZjKeMRz9GtwJ1wTEDD\n\t3hNoZvRbwGQN1L0eeL0T4ud6Q1tAfhbx6gZzMnkH5TdWFtn88ymbczeJE2z5fUyz64\n\tK9GzDO1KyQ7cgUDQWtXenROnJnlNyfsOZq9m3e6cOHw+MEAAsuWzhbKUYGCBCrtKv1\n\tlAWXmfJmBG9HFGRZusY2RXtKfZZ/kIQ7DvB6rukrgdYTe0G5B5pugVilXLjsEmo90U\n\t2x6C585CkyvnA==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1669301157;\n\tbh=k1m8QQ1vKRcT8Yf95deLGhvehL5TdbzwSo0aCazGe8Y=;\n\th=From:To:Cc:Subject:Date:From;\n\tb=Oymq002ieUJL/iMdDeBkNElHdXAjZ+bx4mbAwHPEFxpMM5psSyP7gWcKxgvbIF/Vz\n\tlc4S0kHQE2Dxl5VBAQz160G0LmG5U5ep03BfbGrX8Fo5L1aghh/T3voK2F+Gk7c/QK\n\tbV+aQA89owCmyyTcfyyH/zacSr3Gmts6BlBudZtQ="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"Oymq002i\"; dkim-atps=neutral","To":"libcamera devel ","Date":"Thu, 24 Nov 2022 14:45:53 +0000","Message-Id":"<20221124144553.3012369-1-kieran.bingham@ideasonboard.com>","X-Mailer":"git-send-email 2.34.1","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v5] libcamera: v4l2_device: Workaround\n\tfaulty control menus","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 ","Cc":"Marian Buschsieweke ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Some UVC cameras have been identified that can provide V4L2 menu\ncontrols without any menu items.\n\nThis leads to a segfault where we try to construct a\nControlInfo(Span<>,default) with an empty span.\n\nConvert the v4l2ControlInfo and v4l2MenuControlInfo helper functions to\nreturn std::optional to be able to account in the caller if\nthe control is valid, and only add acceptable controls to the supported\ncontrol list.\n\nMenu controls without a list of menu items are no longer added as a\nvalid control and a warning is logged.\n\nThis also fixes a potential crash that would have occured in the\nunlikely event that a ctrl.minimum was set to less than 0.\n\nBug: https://bugs.libcamera.org/show_bug.cgi?id=167\nReported-by: Marian Buschsieweke \nReviewed-by: Jacopo Mondi \nSigned-off-by: Kieran Bingham \n---\n\nAs I posted two v3 patches, I've gone straight to v5 on this.\n\nNow there's only the common path error report, and a couple of minor\ntext fixes.\n\n\n include/libcamera/internal/v4l2_device.h | 4 ++--\n src/libcamera/v4l2_device.cpp | 28 +++++++++++++++++++-----\n 2 files changed, 25 insertions(+), 7 deletions(-)","diff":"diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h\nindex 75304be11f77..50d4adbc5f2b 100644\n--- a/include/libcamera/internal/v4l2_device.h\n+++ b/include/libcamera/internal/v4l2_device.h\n@@ -70,8 +70,8 @@ protected:\n private:\n \tstatic ControlType v4l2CtrlType(uint32_t ctrlType);\n \tstatic std::unique_ptr v4l2ControlId(const v4l2_query_ext_ctrl &ctrl);\n-\tControlInfo v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl);\n-\tControlInfo v4l2MenuControlInfo(const v4l2_query_ext_ctrl &ctrl);\n+\tstd::optional v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl);\n+\tstd::optional v4l2MenuControlInfo(const v4l2_query_ext_ctrl &ctrl);\n \n \tvoid listControls();\n \tvoid updateControls(ControlList *ctrls,\ndiff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\nindex c17b323f8af0..57a88d96b12c 100644\n--- a/src/libcamera/v4l2_device.cpp\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -529,7 +529,7 @@ std::unique_ptr V4L2Device::v4l2ControlId(const v4l2_query_ext_ctrl &\n * \\param[in] ctrl The v4l2_query_ext_ctrl that represents a V4L2 control\n * \\return A ControlInfo that represents \\a ctrl\n */\n-ControlInfo V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl)\n+std::optional V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl)\n {\n \tswitch (ctrl.type) {\n \tcase V4L2_CTRL_TYPE_U8:\n@@ -566,14 +566,14 @@ ControlInfo V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl)\n *\n * \\return A ControlInfo that represents \\a ctrl\n */\n-ControlInfo V4L2Device::v4l2MenuControlInfo(const struct v4l2_query_ext_ctrl &ctrl)\n+std::optional V4L2Device::v4l2MenuControlInfo(const struct v4l2_query_ext_ctrl &ctrl)\n {\n \tstd::vector indices;\n \tstruct v4l2_querymenu menu = {};\n \tmenu.id = ctrl.id;\n \n \tif (ctrl.minimum < 0)\n-\t\treturn ControlInfo();\n+\t\treturn std::nullopt;\n \n \tfor (int32_t index = ctrl.minimum; index <= ctrl.maximum; ++index) {\n \t\tmenu.index = index;\n@@ -583,6 +583,14 @@ ControlInfo V4L2Device::v4l2MenuControlInfo(const struct v4l2_query_ext_ctrl &ct\n \t\tindices.push_back(index);\n \t}\n \n+\t/*\n+\t * Some faulty UVC devices are known to return an empty menu control.\n+\t * Controls without a menu option can not be set, or read, so they are\n+\t * not exposed.\n+\t */\n+\tif (indices.size() == 0)\n+\t\treturn std::nullopt;\n+\n \treturn ControlInfo(indices,\n \t\t\t ControlValue(static_cast(ctrl.default_value)));\n }\n@@ -631,7 +639,17 @@ void V4L2Device::listControls()\n \t\tcontrolIdMap_[ctrl.id] = controlIds_.back().get();\n \t\tcontrolInfo_.emplace(ctrl.id, ctrl);\n \n-\t\tctrls.emplace(controlIds_.back().get(), v4l2ControlInfo(ctrl));\n+\t\tstd::optional info = v4l2ControlInfo(ctrl);\n+\n+\t\tif (!info) {\n+\t\t\tLOG(V4L2, Error)\n+\t\t\t\t<< \"Control \" << ctrl.name\n+\t\t\t\t<< \" cannot be registered\";\n+\n+\t\t\tcontinue;\n+\t\t}\n+\n+\t\tctrls.emplace(controlIds_.back().get(), *info);\n \t}\n \n \tcontrols_ = ControlInfoMap(std::move(ctrls), controlIdMap_);\n@@ -670,7 +688,7 @@ void V4L2Device::updateControlInfo()\n \t\t\tcontinue;\n \t\t}\n \n-\t\tinfo = v4l2ControlInfo(ctrl);\n+\t\tinfo = *v4l2ControlInfo(ctrl);\n \t}\n }\n \n","prefixes":["libcamera-devel","v5"]}