From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0363C33A014; Fri, 2 Oct 2026 08:53:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790931205; cv=none; b=qcfvh/ha+nyvfH65vQe1Nwd0d1ZXyrZg3k8AxZMfwYWb0pTjGmvS/zBu2GC46uOtIO5Of5GdX/J4uB6Y/Ae6z56irWU/O3vQ9N5TQ/P7lyATJGHC1vTJfYAr8+K9CvLcX3D4YLoP8YGQAFhyZjjsg75Oy2Xfu7W66dSnsCH58a8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790931205; c=relaxed/simple; bh=OUd46eQf7kwOL/iqEFkEDEC8xb9V7EynRj3WeqAslvE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=s5xGOZNNhq8QkL0SJYcDEfxhKvGfBL8t7K3PKVFcPJbiEVr5izceFD2Qj7mx6KM+SHc0z6sCG7gxyLL+dcZUoUPX4i0KUvqn6zC9IndNbDHJFkMviiu0x8y7VlxIAddSQuoM10CZjvEGQQGA8cJCQsu4cna3DlQr5KYFpXI5HLU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DBLgsM/3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DBLgsM/3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 695581F000FF; Fri, 2 Oct 2026 08:53:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790931203; bh=b76lmn+AfBToq/B+Bidd3cGscxduq21YgiiOj463Xas=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=DBLgsM/3zeV4rGvc/sW/XvcCI79IK89LIgQDxv2Pa+yZHaycy5VUUzbJVK1y1N2i/ 0xBVm0d19PwdrvsiKJkNV8Ctgbd9stZZQ5mRROxs7StS4Gx2umiygRwrkf6P45X7Me y6upBZFkjioytz5al/Lr9uTl/RpRAA9IzFcC8OhSosCE4w13p/xzYAT2mc76JxCROt jZhnWjiiVfBRi/0/vU0M4oQ46ifZlCXK20iIBr+0qTLc1N2hMounanbxMX5DfZC0By 2M/xHuyUsUqd1O995mK03P+R0mo/dZYBDC7+uK3FALirpoyE7m7vFYjI2fA0+MBG4Z IWWljH8q1eEqA== From: Mattijs Korpershoek To: Sakari Ailus Cc: Laurent Pinchart , Kieran Bingham , Mauro Carvalho Chehab , Michael Riesch , Dave Stevenson , Maxime Ripard , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 2/5] media: v4l2-subdev: Add new ioctl for connection status In-Reply-To: References: <20261001-v4l2-sensor-detect-v1-0-a45993be17b8@kernel.org> <20261001-v4l2-sensor-detect-v1-2-a45993be17b8@kernel.org> Date: Fri, 02 Oct 2026 10:53:21 +0200 Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Hi Sakari, On Fri, Oct 02, 2026 at 10:13, Sakari Ailus wrote: > Hi Mattijs, > > On Thu, Oct 01, 2026 at 02:55:20PM +0200, Mattijs Korpershoek wrote: >> The V4L2 framework has historically assumed that every component of the >> camera pipeline is always present. This is a reasonable assumption for >> integrated cameras in laptops or phones. However, in automotive systems, >> cameras (e.g. rear-view or surround-view) can be damaged or >> disconnected. >> >> When a camera gets disconnected, userspace cannot detect this and thus >> cannot react (for example, by disabling streaming on a faulty camera). >> >> Add a new v4l2-subdev ioctl (VIDIOC_SUBDEV_G_CONNECTION_STATUS) that >> drivers can implement to report their connection status. >> >> Signed-off-by: Mattijs Korpershoek > > Have you considered using V4L2 controls for this? I have not considered it. I think I initially wanted to make this a control but I ended up making it an ioctl. >From patch 5/5 in this thread, it seems that you believe that a control is more appropriate. I will look into that for v2. Thanks for the suggestion! Mattijs > > -- > Regards, > > Sakari Ailus