From patchwork Mon May 18 20:15:07 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Mader X-Patchwork-Id: 26770 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 E3CFCC32F4 for ; Mon, 18 May 2026 20:16:20 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 1B04663030; Mon, 18 May 2026 22:16:20 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=collabora.com header.i=robert.mader@collabora.com header.b="PNFt2HX3"; dkim-atps=neutral Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 66AAB62FEC for ; Mon, 18 May 2026 22:16:17 +0200 (CEST) ARC-Seal: i=1; a=rsa-sha256; t=1779135374; cv=none; d=zohomail.com; s=zohoarc; b=BoI6IYUyGmA6C3yKidp4zEIpJ9mn6zjMSTeH3NJ9mQntgPbiRnmLJxU7xUIbkm2hkWAktkMZDgOaUptb/2bk/7Jm0k73vjdQRC58Io+Vo8wk9MdP7Ot7W+mUb32Qv440tqtYhuVsnATLcQZOlV/Iuj669lvy8HegfFR254zmzQk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1779135374; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=hTPfehAIGuGVuZradoz4Gns7kWlYb3dOc1wahtblfyQ=; b=btEmtU0AuB3fjHxrO+RdlpqN7+N4PI8Xh9jk167NkIjQDnHgimLk4HOkDB16K35DhRtsP+VbNwa13KOtqUSFY2TWN9VZZF3lFZjtBAnBkKP715MnaH9yOrRPJLPZn7WspPq8z3po0pTny14XsARPJm6vQXXUZQ2gd88483S7/w0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=robert.mader@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1779135374; s=zohomail; d=collabora.com; i=robert.mader@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=hTPfehAIGuGVuZradoz4Gns7kWlYb3dOc1wahtblfyQ=; b=PNFt2HX3I81vw2CZ6xAa+izmZ7EMbacpYhVl66gu9fDm08yGeYSQYlRSOVK5VSyv qNaI1SWd8vicAefXC5ElxNp+jx/Ry4wtZJakIrpTFHphAQ+MEH7QtqpeVOH/b/QWToo vpOnMmzKS+jyqg58pHWJn6XUEIFv7bV1iyyU0Ch8= Received: by mx.zohomail.com with SMTPS id 1779135373467224.49950436502218; Mon, 18 May 2026 13:16:13 -0700 (PDT) From: Robert Mader To: libcamera-devel@lists.libcamera.org Cc: Robert Mader Subject: [PATCH v2 3/4] debayer_egl: Implement dmabuf import for input buffers Date: Mon, 18 May 2026 22:15:07 +0200 Message-ID: <20260518201508.140849-4-robert.mader@collabora.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260518201508.140849-1-robert.mader@collabora.com> References: <20260518201508.140849-1-robert.mader@collabora.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" In many cases we can import the GPU-ISP input buffers, dmabufs from v4l2, directly into EGL instead of mapping and uploading - i.e. copying - them. Doing so can have positive effects in multiple areas, including reducing memory bandwidth and CPU usage, as well as avoiding expensive dmabuf syncs and syscalls. The main reason direct imports may not work are the more demanding stride alignment requirements many GPUs have - often 128 or 256 bytes - compared to ISPs - apparently often closer to 32 bytes. Thus we first try to import buffers directly and - if that fails - fall back to the previous upload path. Failing imports should come at low cost as drivers know the limitations and can bail out early, without causing additional IO or context switches. In the future we might be able to request buffers with a matching stride from v4l2 drivers in many cases, making direct import the norm instead of a hit-or-miss. An optional kernel API for that exists, but doesn't seem to be implemented by any driver tested so far. While on it, add some minor code adjustments to make it easier to follow. Signed-off-by: Robert Mader --- src/libcamera/software_isp/debayer_egl.cpp | 32 ++++++++++++---------- src/libcamera/software_isp/debayer_egl.h | 2 +- 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp index a217e3798..e5a661d2c 100644 --- a/src/libcamera/software_isp/debayer_egl.cpp +++ b/src/libcamera/software_isp/debayer_egl.cpp @@ -500,16 +500,26 @@ void DebayerEGL::setShaderVariableValues(const DebayerParams ¶ms) return; } -int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms) +int DebayerEGL::debayerGPU(FrameBuffer *input, std::optional *inputBufferDmaSyncer, FrameBuffer *output, const DebayerParams ¶ms) { /* eGL context switch */ egl_.makeCurrent(); /* Create a standard texture input */ - egl_.createTexture2D(*eglImageBayerIn_, in.planes()[0].data()); + if (egl_.createInputDMABufTexture2D(*eglImageBayerIn_, input->planes()[0].fd.get()) != 0) { + LOG(Debayer, Debug) << "Importing input buffer with DMABuf import failed, falling back to upload"; + + inputBufferDmaSyncer->emplace(input->planes()[0].fd, DmaSyncer::SyncType::Read); + MappedFrameBuffer in(input, MappedFrameBuffer::MapFlag::Read); + if (!in.isValid()) { + LOG(Debayer, Error) << "mmap-ing buffer(s) failed"; + return -ENODEV; + } + egl_.createTexture2D(*eglImageBayerIn_, in.planes()[0].data()); + } /* Generate the output render framebuffer as render to texture */ - egl_.createOutputDMABufTexture2D(*eglImageBayerOut_, out_fd); + egl_.createOutputDMABufTexture2D(*eglImageBayerOut_, output->planes()[0].fd.get()); setShaderVariableValues(params); glViewport(0, 0, width_, height_); @@ -531,23 +541,15 @@ void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output { bench_.startFrame(); - std::vector dmaSyncers; - - dmaSyncBegin(dmaSyncers, input, nullptr); - /* Copy metadata from the input buffer */ FrameMetadata &metadata = output->_d()->metadata(); metadata.status = input->metadata().status; metadata.sequence = input->metadata().sequence; metadata.timestamp = input->metadata().timestamp; - MappedFrameBuffer in(input, MappedFrameBuffer::MapFlag::Read); - if (!in.isValid()) { - LOG(Debayer, Error) << "mmap-ing buffer(s) failed"; - goto error; - } + std::optional inputBufferDmaSyncer; - if (debayerGPU(in, output->planes()[0].fd.get(), params)) { + if (debayerGPU(input, &inputBufferDmaSyncer, output, params)) { LOG(Debayer, Error) << "debayerGPU failed"; goto error; } @@ -557,8 +559,10 @@ void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output metadata.planes()[0].bytesused = output->planes()[0].length; /* Calculate stats for the whole frame */ + if (!inputBufferDmaSyncer && (frame % SwStatsCpu::kStatPerNumFrames) == 0) + inputBufferDmaSyncer.emplace(input->planes()[0].fd, DmaSyncer::SyncType::Read); stats_->processFrame(frame, 0, input); - dmaSyncers.clear(); + inputBufferDmaSyncer.reset(); outputBufferReady.emit(output); inputBufferReady.emit(input); diff --git a/src/libcamera/software_isp/debayer_egl.h b/src/libcamera/software_isp/debayer_egl.h index 141fb288f..a98a8139a 100644 --- a/src/libcamera/software_isp/debayer_egl.h +++ b/src/libcamera/software_isp/debayer_egl.h @@ -65,7 +65,7 @@ private: int initBayerShaders(PixelFormat inputFormat, PixelFormat outputFormat); int getShaderVariableLocations(); void setShaderVariableValues(const DebayerParams ¶ms); - int debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms); + int debayerGPU(FrameBuffer *input, std::optional *inputBufferDmaSyncer, FrameBuffer *output, const DebayerParams ¶ms); /* Shader program identifiers */ GLuint vertexShaderId_ = 0;