From patchwork Wed Mar 13 07:24:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 13591078 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 4F92C179B8 for ; Wed, 13 Mar 2024 07:25:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710314756; cv=none; b=M+YVHGlxbmtZ9JegG3WovZnOcClPNOjQS7j4CWL5rHm5UtYX9ahSWuD8KickkyV9XCngQxzOqbeR+BGA7Xbxpb66arHvYQlNr0nZ33L+7dzexIC0J2NgTyhpPlUyDqbzP2llzisj1Cu0hDNNb0QElZ/SPodU1xCuknDifUyzBes= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710314756; c=relaxed/simple; bh=5CEumrArqSn3mQB8bdKjqdG7hHq439rMO0PeqsSMsHo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XonhT6WrOHft57prrN+JlZSC9zMaIPMEqnpUvKL0niL9rNCwrGbo9yg/wZZYd3tofO/JmV85dKaFLO0fk1qdXdgNGJYAfjH9jw4ZV/OLglXemkK9ZiMp4EV67RZkyasQd8gku/ZYKKCcMDqWh5uYvofPh/N9Z1G5gpW0WkxmiDE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=j3jH8jaz; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="j3jH8jaz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710314755; x=1741850755; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5CEumrArqSn3mQB8bdKjqdG7hHq439rMO0PeqsSMsHo=; b=j3jH8jazU/iZGqpi41cfSi6kUW21N/sEDpFAUiMCIktQbjV03GeTQ1qB OIJyWPk0Cr2g1JNq78aGw/kJviY3/DbKu+iOQZbYtNQbjf8drt2u6uG2C O9hMwrxOG3b8xyGoqjK8yD77B9fq78zWcNiJlJFo/5NO3x+5HrRb/vvkz hf69l2laQXIISQt9NTo8WqrsPoGArAr7hlE9oK7h0a5RTTUG9F3xsi91i ThdK9JiuvutA1RsyDe9e8XbmWiMD1RR3PyM3Gw9v+T4lr7yl8rwRaOLRZ d55AJIqQlXJA8XFtf7cHyjC5qGBtLSU8wP2pSoCtCrbVxmg9ZUVg4EtxN w==; X-IronPort-AV: E=McAfee;i="6600,9927,11011"; a="22575577" X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="22575577" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Mar 2024 00:25:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="42816407" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Mar 2024 00:25:38 -0700 Received: from svinhufvud.ger.corp.intel.com (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with ESMTP id CBB121206F9; Wed, 13 Mar 2024 09:25:34 +0200 (EET) From: Sakari Ailus To: linux-media@vger.kernel.org Cc: Laurent Pinchart , tomi.valkeinen@ideasonboard.com, bingbu.cao@intel.com, hongju.wang@intel.com, hverkuil@xs4all.nl, Andrey Konovalov , Jacopo Mondi , Dmitry Perchanov , "Ng, Khai Wen" , Alain Volmat Subject: [PATCH v8 11/38] media: v4l: subdev: Add a function to lock two sub-device states, use it Date: Wed, 13 Mar 2024 09:24:49 +0200 Message-Id: <20240313072516.241106-12-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240313072516.241106-1-sakari.ailus@linux.intel.com> References: <20240313072516.241106-1-sakari.ailus@linux.intel.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add two new functions, v4l2_subdev_lock_states() and v4l2_subdev_unclock_states(), to acquire and release the state of two sub-devices. They differ from calling v4l2_subdev_{un,}lock_state() so that if the two states share the same lock, the lock is acquired only once. Also use the new functions in v4l2_subdev_link_validate(). Signed-off-by: Sakari Ailus Reviewed-by: Julien Massot Reviewed-by: Laurent Pinchart --- drivers/media/v4l2-core/v4l2-subdev.c | 12 +++----- include/media/v4l2-subdev.h | 40 +++++++++++++++++++++++++++ 2 files changed, 44 insertions(+), 8 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 4c6198c48dd6..6c34df19ea2f 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -1400,17 +1400,13 @@ int v4l2_subdev_link_validate(struct media_link *link) states_locked = sink_state && source_state; - if (states_locked) { - v4l2_subdev_lock_state(sink_state); - v4l2_subdev_lock_state(source_state); - } + if (states_locked) + v4l2_subdev_lock_states(sink_state, source_state); ret = v4l2_subdev_link_validate_locked(link, states_locked); - if (states_locked) { - v4l2_subdev_unlock_state(sink_state); - v4l2_subdev_unlock_state(source_state); - } + if (states_locked) + v4l2_subdev_unlock_states(sink_state, source_state); return ret; } diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index a9e6b8146279..9cce48365975 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -1724,6 +1724,46 @@ static inline void v4l2_subdev_unlock_state(struct v4l2_subdev_state *state) mutex_unlock(state->lock); } +/** + * v4l2_subdev_lock_states - Lock two sub-device states + * @state1: One subdevice state + * @state2: The other subdevice state + * + * Locks the state of two sub-devices. + * + * The states must be unlocked with v4l2_subdev_unlock_states() after use. + * + * This differs from calling v4l2_subdev_lock_state() on both states so that if + * the states share the same lock, the lock is acquired only once (so no + * deadlock occurs). The caller is responsible for ensuring the locks will + * always be acquired in the same order. + */ +static inline void v4l2_subdev_lock_states(struct v4l2_subdev_state *state1, + struct v4l2_subdev_state *state2) +{ + mutex_lock(state1->lock); + if (state1->lock != state2->lock) + mutex_lock(state2->lock); +} + +/** + * v4l2_subdev_unlock_states() - Unlock two sub-device states + * @state1: One subdevice state + * @state2: The other subdevice state + * + * Unlocks the state of two sub-devices. + * + * This differs from calling v4l2_subdev_unlock_state() on both states so that + * if the states share the same lock, the lock is released only once. + */ +static inline void v4l2_subdev_unlock_states(struct v4l2_subdev_state *state1, + struct v4l2_subdev_state *state2) +{ + mutex_unlock(state1->lock); + if (state1->lock != state2->lock) + mutex_unlock(state2->lock); +} + /** * v4l2_subdev_get_unlocked_active_state() - Checks that the active subdev state * is unlocked and returns it