From nobody Fri Dec 19 22:01:10 2025 Received: from mail-vs1-f42.google.com (mail-vs1-f42.google.com [209.85.217.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3ACCC86321 for ; Tue, 7 Jan 2025 15:23:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.217.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736263424; cv=none; b=Vd+0gtTOd/dUJRSdhu6T78HGcRPQ0ycPDQ6t1bu8L9KQYqxAoVUkp6gSg494kV439pvxugfO5iGER6H3dNZ7HmiLzZn+ZIz0s2QWaAcW9HRdNBYqC+V4RVyzkmCHLHU3N1hkUw2ELPiAqKrfHgkyFgaziPAjtnRB5IXswuMjxsA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736263424; c=relaxed/simple; bh=Sj9hUan73Ec622PoPDJGjTAagERBAGH09/QZYg9H7SA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=mE3zTZlYKEyGRiPuh67cfHBWudU/5hqRT4bkykuGcr2xi7BPy+9Fb9cBxeAV9du1KfAIXLDW/OO1BtUluljw1rIqqVAYTxC8UcePWFCy9GNfKVohdUk+oKoV9b8L+o6FCBRbgODnoAjUXIeIVwAq55vO7VvOh3yV195h+v2CkgA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=G0PTXVkf; arc=none smtp.client-ip=209.85.217.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="G0PTXVkf" Received: by mail-vs1-f42.google.com with SMTP id ada2fe7eead31-4afecb2731dso4282017137.3 for ; Tue, 07 Jan 2025 07:23:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1736263420; x=1736868220; darn=vger.kernel.org; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:from:to:cc:subject:date:message-id:reply-to; bh=txt9C05Azavh1d6lKAx/rakp7gfsIdtNOiWVgM2m56I=; b=G0PTXVkfBDpW488RRnNJ4oBbt3xXaaOJ2hkVd5584uWqIWt5ypqRceXq3Lmbw72Mpm By1PepQOr+onMS96QzjaoZR6MStVfgOcx9qrUByETNrfvtE0AvPUa2YyogBQ5YZoTWlA YGLaexBTsZiMGV4eA1IHHI4Upu1FxGtbip1ec= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736263420; x=1736868220; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=txt9C05Azavh1d6lKAx/rakp7gfsIdtNOiWVgM2m56I=; b=HhYBeidkVRM3Musp7FBq1zce+HWvGykJqw8/p0h3m7HzjAziO8/2B41CinYW7mBt/i zLDhaStBVZp4k8ig6cbRsn+GuZU64OtJP/KM8USZ7de+2FLqVCbkRZrZSStjiyI7V0J/ SZr2sOMfmTgBgNhY0M+fjkCMz0w+w5LxGIdflHIDrm461Yu707nqvujGPxzTNLlJztqn 56RytU1L7vLo2meu9Tclm+nqf7YHEE5j+6L/oVmv99Yup3qs5c/iJfKAGaU6fWAr14sl +bVeceBB65OC00hUwMcGXpMRK/Kb3JfHasjYvpXbNbmP8Zv7hDFC1NMFUxnyZ+M7DkXA sh5w== X-Forwarded-Encrypted: i=1; AJvYcCWaikdCiKz/0T0IcwcxET7QNIL1LmJgcDEJitpntpDRh7OjSVz2DoNU+XDMU1bvHV0RJ+XpE+NNGxfOLHs=@vger.kernel.org X-Gm-Message-State: AOJu0Yw13CQf6knErAscmSf9FFMvBfOL9QOj5DH+mtrDjHdCJeo15am4 gCLcHH7k9g75mEI13tbLv7a3aJcdDTqDKwQZAGjAcCmPfSlj9uiCYxNVlAXAew== X-Gm-Gg: ASbGnctvK42r84bIddQvTdMry/PVJgHSTY2gJ9LtyXhb681FVCnfRBo3NnkSuhv8iME HKAn/OBOCFbhdEfsMIpMTKhlbyqZutfn/oBoy7dun9suFpGK1YeYC9NUzcZ5EIrUGetv06CzRJC QFit7yODux/YpocfNhfB3htBEWQ3WYGA5Hl2gHwjjDrcTC329GsA+uwlDAPrdVGmrazjjib/3KW 1XoViDII1htJnteU2V3ujV8Mmxrq8+G4+IRZehsGvDqZhHy1xM6rRNfkf9ceB1vnN2OyOSwzhWZ xDc4T/eoqhKax1NAgAV9l0mp5bnBuSWKtF6N X-Google-Smtp-Source: AGHT+IGh4ONZ44qnwldtexGBq+3szPow5XWsqDzBusHDbDQ9KdOedZ3AszSwm/ZvlpUI/CKvQ4yClQ== X-Received: by 2002:a05:6102:50a1:b0:4af:d487:45f3 with SMTP id ada2fe7eead31-4b2cc49a842mr46825080137.23.1736263420157; Tue, 07 Jan 2025 07:23:40 -0800 (PST) Received: from denia.c.googlers.com (172.174.245.35.bc.googleusercontent.com. [35.245.174.172]) by smtp.gmail.com with ESMTPSA id ada2fe7eead31-4b2bfad517dsm7977915137.31.2025.01.07.07.23.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jan 2025 07:23:39 -0800 (PST) From: Ricardo Ribalda Date: Tue, 07 Jan 2025 15:23:38 +0000 Subject: [PATCH v3] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 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: <20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org> X-B4-Tracking: v=1; b=H4sIAPlGfWcC/23Myw6CMBCF4Vchs7amF6joyvcwLmAYYBZQ0kqjI by7hZUal+ck379AIM8U4JIt4ClyYDemYQ4ZYF+NHQlu0gYtda60MmKOKKhCpBDEqSgQpVWVsRK SmDy1/Nxrt3vaPYeH8689HtX2/u9EJZSwmmSdt4jW5FfsvRt4Ho7Od7Clov7k52+uE69bW2iJZ V3a5oev6/oGzZRM1egAAAA= To: Hans Verkuil , Laurent Pinchart , Hans de Goede , Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Ricardo Ribalda X-Mailer: b4 0.13.0 To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, step and flags of the control. For some of the controls, this involves querying the actual hardware. Some non-compliant cameras produce errors when we query them. Right now, we populate that error to userspace. When an error happens, the v4l2 framework does not copy the v4l2_queryctrl struct to userspace. Also, userspace apps are not ready to handle any other error than -EINVAL. One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In that usecase, a non-compliant control will make it almost impossible to enumerate all controls of the device. A control with an invalid max/min/step/flags is better than non being able to enumerate the rest of the controls. This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases different than -EINVAL, introduces a warning in dmesg so we can have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. Signed-off-by: Ricardo Ribalda --- Hi 2*Hans and Laurent! I came around a device that was listing just a couple of controls when it should be listing much more. Some debugging latter I found that the device was returning -EIO when all the focal controls were read. Lots of good arguments in favor/against this patch in the v1. Please check! Without this patch: $ v4l2-ctl --list-ctrls auto_exposure 0x009a0901 (menu) : min=3D0 max=3D3 defau= lt=3D3 value=3D3 (Aperture Priority Mode) exposure_time_absolute 0x009a0902 (int) : min=3D50 max=3D10000 = step=3D1 default=3D166 value=3D166 flags=3Dinactive exposure_dynamic_framerate 0x009a0903 (bool) : default=3D0 value=3D0 region_of_interest_auto_control 0x009a1902 (bitmask): max=3D0x00000001 defa= ult=3D0x00000001 value=3D1 With this patch: $ v4l2-ctl --list-ctrls auto_exposure 0x009a0901 (menu) : min=3D0 max=3D3 defau= lt=3D3 value=3D3 (Aperture Priority Mode) exposure_time_absolute 0x009a0902 (int) : min=3D50 max=3D10000 = step=3D1 default=3D166 value=3D166 flags=3Dinactive exposure_dynamic_framerate 0x009a0903 (bool) : default=3D0 value=3D0 error 5 getting ext_ctrl Focus, Absolute error 5 getting ext_ctrl Focus, Automatic Continuous region_of_interest_rectangle 0x009a1901 (unknown): type=3D107 value=3Dun= supported payload type flags=3Dhas-payload region_of_interest_auto_control 0x009a1902 (bitmask): max=3D0x00000001 defa= ult=3D0x00000001 value=3D1 -- --- Changes in v3: - Add a retry mechanism during error. - Set V4L2_CTRL_FLAG_DISABLED flag. - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b= 86d@chromium.org Changes in v2: - Never return error, even if we are not enumerating the controls - Improve commit message. - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc= 634@chromium.org --- drivers/media/usb/uvc/uvc_ctrl.c | 41 ++++++++++++++++++++++++++++++++----= ---- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_c= trl.c index 4e58476d305e..d69b9efa74d0 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ct= rl, return ~0; } =20 +#define MAX_QUERY_RETRIES 2 + static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, struct uvc_control *ctrl, struct uvc_control_mapping *mapping, @@ -1305,19 +1307,42 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_c= hain *chain, __uvc_find_control(ctrl->entity, mapping->master_id, &master_map, &master_ctrl, 0); if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { + unsigned int retries; s32 val; - int ret =3D __uvc_ctrl_get(chain, master_ctrl, master_map, &val); - if (ret < 0) - return ret; + int ret; =20 - if (val !=3D mapping->master_manual) - v4l2_ctrl->flags |=3D V4L2_CTRL_FLAG_INACTIVE; + for (retries =3D 0; retries < MAX_QUERY_RETRIES; retries++) { + ret =3D __uvc_ctrl_get(chain, master_ctrl, master_map, + &val); + if (ret >=3D 0) + break; + } + + if (ret < 0) { + dev_warn_ratelimited(&chain->dev->udev->dev, + "UVC non compliance: Error %d querying master control %x\n", + ret, master_map->id); + } else if (val !=3D mapping->master_manual) { + v4l2_ctrl->flags |=3D V4L2_CTRL_FLAG_INACTIVE; + } } =20 if (!ctrl->cached) { - int ret =3D uvc_ctrl_populate_cache(chain, ctrl); - if (ret < 0) - return ret; + unsigned int retries; + int ret; + + for (retries =3D 0; retries < MAX_QUERY_RETRIES; retries++) { + ret =3D uvc_ctrl_populate_cache(chain, ctrl); + if (ret >=3D 0) + break; + } + + if (ret < 0) { + dev_warn_ratelimited(&chain->dev->udev->dev, + "UVC non compliance: Error %d populating cache of control %x\n", + ret, mapping->id); + v4l2_ctrl->flags |=3D V4L2_CTRL_FLAG_DISABLED; + } } =20 if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { --- base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 change-id: 20241213-uvc-eaccess-755cc061a360 Best regards, --=20 Ricardo Ribalda