From patchwork Tue Oct 27 21:24:46 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 28651 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 09079C3302 for ; Tue, 27 Oct 2026 21:24:59 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 3A8BC69069; Tue, 27 Oct 2026 22:24:57 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="MWDLCXeh"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 3008569059 for ; Tue, 27 Oct 2026 22:24:53 +0100 (CET) Received: from killaraus.ideasonboard.com (2001-14ba-70f3-e800--a06.rev.dnainternet.fi [IPv6:2001:14ba:70f3:e800::a06]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D45FD4BB for ; Tue, 27 Oct 2026 22:22:40 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1793136161; bh=znBtFpnTIvh28TAIbShinuerBWcwv1okipom30ndFnY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=MWDLCXehLo6DJNe3S1EKKXhWzOvIvEdaLV0ekvfVVboC0e0Ip6figyK3ZnSgsAR3r lD6dSQOaRGOfuM1wI/nkL0X7sVTY993l5cCFNImcvij2Tj/F1v7UZ5FdeAv3DL97O5 d4lrB5+KfItXSebaC/OCV4C8WAZA12KQmXwrQdCg= From: Laurent Pinchart To: libcamera-devel@lists.libcamera.org Subject: [PATCH 3/4] v4l2: v4l2_camera_proxy: Clear ERROR flag when dequeuing or stopping streaming Date: Tue, 27 Oct 2026 23:24:46 +0200 Message-ID: <20261027212447.2551591-4-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261027212447.2551591-1-laurent.pinchart@ideasonboard.com> References: <20261027212447.2551591-1-laurent.pinchart@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" When a buffer is dequeued with VIDIOC_DQBUF, the V4L2 API reports buffer erros with the V4L2_BUF_FLAG_ERROR. The API documentation doesn't state what flags a subsequent VIDIOC_QUERYBUF call should return for the same buffer, but videobuf2 sets the buffer state to dequeued just before returning from VIDIOC_DQBUF, effectively clearing V4L2_BUF_FLAG_ERROR. Similarly, a call to VIDIOC_STREAMOFF also put all queued buffers back in the dequeued state. Implement the same behaviour and clear the flag in vidioc_dqbuf() and vidioc_streamoff(). This issue isn't caught by v4l2-compliance. Signed-off-by: Laurent Pinchart Reviewed-by: Jacopo Mondi Reviewed-by: Kieran Bingham --- src/v4l2/v4l2_camera_proxy.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp index 2786e29e1ed7..03b8a4210046 100644 --- a/src/v4l2/v4l2_camera_proxy.cpp +++ b/src/v4l2/v4l2_camera_proxy.cpp @@ -698,6 +698,8 @@ int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg, buf.length = sizeimage_; *arg = buf; + buf.flags &= ~V4L2_BUF_FLAG_ERROR; + currentBuf_ = (currentBuf_ + 1) % bufferCount_; uint64_t data; @@ -778,7 +780,7 @@ int V4L2CameraProxy::vidioc_streamoff(V4L2CameraFile *file, int *arg) for (struct v4l2_buffer &buf : buffers_) buf.flags &= ~(V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE | - V4L2_BUF_FLAG_PREPARED); + V4L2_BUF_FLAG_ERROR | V4L2_BUF_FLAG_PREPARED); return ret; }