From patchwork Tue Aug 20 19:50:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 20979 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 84097C323E for ; Tue, 20 Aug 2024 19:50:34 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 2F3B9633CC; Tue, 20 Aug 2024 21:50:34 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="C6he7EkT"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id BB326633CE for ; Tue, 20 Aug 2024 21:50:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724183429; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yv03rFPwncxEXqXKc75XE90oiiULTRtFAXKnU/3UDfE=; b=C6he7EkTlcQODQmIVqOnp6vTMxF1Rmb24eyvv3gkgoOeUqEfwfhbu1Y81uy0OiXYpuM9FD n/1UFQeDTH12UeBenD3g0bSdnBAYLHAoihc5XqrhEDJd38RNLutbMfeAm1K1rqhO8NnSuB RNidJlkC8no5e2vNInxNRV5VeqUdkqU= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-480-fgjgkCGoOvmhUpX8d272Gw-1; Tue, 20 Aug 2024 15:50:28 -0400 X-MC-Unique: fgjgkCGoOvmhUpX8d272Gw-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 816FF1955D50 for ; Tue, 20 Aug 2024 19:50:27 +0000 (UTC) Received: from x1.localdomain.com (unknown [10.39.192.41]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8007419560AA; Tue, 20 Aug 2024 19:50:25 +0000 (UTC) From: Hans de Goede To: libcamera-devel@lists.libcamera.org Cc: Maxime Ripard , Milan Zamazal , Hans de Goede Subject: [PATCH 3/5] pipeline_handler: Add acquireDevice() method to mirror existing releaseDevice() Date: Tue, 20 Aug 2024 21:50:14 +0200 Message-ID: <20240820195016.16028-4-hdegoede@redhat.com> In-Reply-To: <20240820195016.16028-1-hdegoede@redhat.com> References: <20240820195016.16028-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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" ATM libcamera always keeps all /dev/video# and /dev/v4l2_subdev# nodes for a pipeline open after enumerating the camera. This is a problem for uvcvideo and atomisp /dev/video# nodes as well as for VCM /dev/v4l2_subdev# nodes. Keeping these open stops the underlying hw-devices from being able to enter runtime-suspend causing significant unnecessary power-usage. Add a stub acquireDevice() method to the PipelineHandler class which pipeline handlers can override to delay opening /dev nodes until the camera is acquired. Note pipeline handlers typically also will need access to /dev nodes for their CameraConfig::validate() implementation for tryFormat() calls. Making sure that /dev nodes are opened as necessary from validate() is left up to the pipeline handler implementation. Signed-off-by: Hans de Goede --- include/libcamera/internal/pipeline_handler.h | 3 +- src/libcamera/camera.cpp | 2 +- src/libcamera/pipeline_handler.cpp | 43 +++++++++++++++---- 3 files changed, 37 insertions(+), 11 deletions(-) diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h index cad5812f..597f7c3e 100644 --- a/include/libcamera/internal/pipeline_handler.h +++ b/include/libcamera/internal/pipeline_handler.h @@ -45,7 +45,7 @@ public: MediaDevice *acquireMediaDevice(DeviceEnumerator *enumerator, const DeviceMatch &dm); - bool acquire(); + bool acquire(Camera *camera); void release(Camera *camera); virtual std::unique_ptr generateConfiguration(Camera *camera, @@ -79,6 +79,7 @@ protected: virtual int queueRequestDevice(Camera *camera, Request *request) = 0; virtual void stopDevice(Camera *camera) = 0; + virtual bool acquireDevice(Camera *camera); virtual void releaseDevice(Camera *camera); CameraManager *manager_; diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp index 382a68f7..4e393f89 100644 --- a/src/libcamera/camera.cpp +++ b/src/libcamera/camera.cpp @@ -995,7 +995,7 @@ int Camera::acquire() if (ret < 0) return ret == -EACCES ? -EBUSY : ret; - if (!d->pipe_->acquire()) { + if (!d->pipe_->acquire(this)) { LOG(Camera, Info) << "Pipeline handler in use by another process"; return -EBUSY; diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp index 1fc22d6a..e1342306 100644 --- a/src/libcamera/pipeline_handler.cpp +++ b/src/libcamera/pipeline_handler.cpp @@ -163,20 +163,22 @@ MediaDevice *PipelineHandler::acquireMediaDevice(DeviceEnumerator *enumerator, * has already acquired it * \sa release() */ -bool PipelineHandler::acquire() +bool PipelineHandler::acquire(Camera *camera) { MutexLocker locker(lock_); - if (useCount_) { - ++useCount_; - return true; + if (useCount_ == 0) { + for (std::shared_ptr &media : mediaDevices_) { + if (!media->lock()) { + unlockMediaDevices(); + return false; + } + } } - for (std::shared_ptr &media : mediaDevices_) { - if (!media->lock()) { - unlockMediaDevices(); - return false; - } + if (!acquireDevice(camera)) { + unlockMediaDevices(); + return false; } ++useCount_; @@ -213,12 +215,35 @@ void PipelineHandler::release(Camera *camera) --useCount_; } +/** + * \brief Acquire resources associated with this camera + * \param[in] camera The camera for which to acquire resources + * + * Pipeline handlers may override this in order to get resources + * such as open /dev nodes are allocate buffers when a camera is + * acquired. + * + * Note this is called once for every camera which is acquired, + * so if there are shared resources the pipeline handler must take + * care to not release them until releaseDevice() has been called for + * all previously acquired cameras. + * + * \return True on success, false on failure. + * \sa releaseDevice() + */ +bool PipelineHandler::acquireDevice([[maybe_unused]] Camera *camera) +{ + return true; +} + /** * \brief Release resources associated with this camera * \param[in] camera The camera for which to release resources * * Pipeline handlers may override this in order to perform cleanup operations * when a camera is released, such as freeing memory. + * + * \sa acquireDevice() */ void PipelineHandler::releaseDevice([[maybe_unused]] Camera *camera) {