{"id":17845,"url":"https://patchwork.libcamera.org/api/patches/17845/?format=json","web_url":"https://patchwork.libcamera.org/patch/17845/","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":"<20221123134232.1937002-1-kieran.bingham@ideasonboard.com>","date":"2022-11-23T13:42:32","name":"[libcamera-devel,v3] libcamera: v4l2_device: Workaround faulty control menus","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"126d903a5201221787b7cdbc05d65327f47460bb","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/17845/mbox/","series":[{"id":3632,"url":"https://patchwork.libcamera.org/api/series/3632/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=3632","date":"2022-11-23T13:42:32","name":"[libcamera-devel,v3] libcamera: v4l2_device: Workaround faulty control menus","version":3,"mbox":"https://patchwork.libcamera.org/series/3632/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/17845/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/17845/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 B9473BE08B\n\tfor ;\n\tWed, 23 Nov 2022 13:42:37 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 776A36331A;\n\tWed, 23 Nov 2022 14:42:37 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id AC06A63311\n\tfor ;\n\tWed, 23 Nov 2022 14:42:36 +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 227D8890;\n\tWed, 23 Nov 2022 14:42:36 +0100 (CET)"],"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=\"AlMGORfY\"; dkim-atps=neutral","To":"libcamera devel ","Date":"Wed, 23 Nov 2022 13:42:32 +0000","Message-Id":"<20221123134232.1937002-1-kieran.bingham@ideasonboard.com>","X-Mailer":"git-send-email 2.34.1","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v3] 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 \nSigned-off-by: Kieran Bingham \n---\n include/libcamera/internal/v4l2_device.h | 4 ++--\n src/libcamera/v4l2_device.cpp | 23 ++++++++++++++++++-----\n 2 files changed, 20 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..c2e21bdf33b7 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 +583,17 @@ 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 drivers 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\tLOG(V4L2, Warning)\n+\t\t\t<< \"Menu control '\" << ctrl.name << \"' has no entries\";\n+\t\treturn std::nullopt;\n+\t}\n+\n \treturn ControlInfo(indices,\n \t\t\t ControlValue(static_cast(ctrl.default_value)));\n }\n@@ -631,7 +642,9 @@ 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+\t\tif (info)\n+\t\t\tctrls.emplace(controlIds_.back().get(), *info);\n \t}\n \n \tcontrols_ = ControlInfoMap(std::move(ctrls), controlIdMap_);\n@@ -670,7 +683,7 @@ 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","v3"]}