From patchwork Sun Nov 28 13:24:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Niklas_S=C3=B6derlund?= X-Patchwork-Id: 78847 X-Patchwork-Delegate: hverkuil@xs4all.nl Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1mrKJ2-00F1VL-Gy; Sun, 28 Nov 2021 13:33:24 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357636AbhK1Ngi (ORCPT + 1 other); Sun, 28 Nov 2021 08:36:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235495AbhK1Neg (ORCPT ); Sun, 28 Nov 2021 08:34:36 -0500 Received: from mail-wr1-x42d.google.com (mail-wr1-x42d.google.com [IPv6:2a00:1450:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EC88C0619D8 for ; Sun, 28 Nov 2021 05:25:05 -0800 (PST) Received: by mail-wr1-x42d.google.com with SMTP id j3so30500406wrp.1 for ; Sun, 28 Nov 2021 05:25:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ragnatech-se.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nmZRc5ErwsS/Ewa5E1yYdb3LaeQF1fMRo5QVoF/2Eqo=; b=kTvTBvU9M+OjgbkKilv1qHJ9Tl35amBDAAgNPHxFyozJNsVMIjnN2zFe2vaRlfwbDr jCXtJy3h7Wp4kBqBhDPtGT60FagMQU94S45XPiuZURCyKSa2yeZF/j/IeU7NhtWghovL wfFtuBhWOD2s+TCjiccG7KSA89nwfD7mXRSvB/SYj4ASvh9tlWrP/hXI7WOWsEdyida7 J4OfswCjHFn/tWZ1TYdOWyyIn1Uhvu9FAxrqxeBOlRBXy9tvT1mCqX//1S4s5/zlmOPS 3zOBvXkKGf0emnsrapZVzb8Q/BwXabMKWsspZPaNQ3HRpIPyE/8Jr76+6iASgR4jj5XV fHvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nmZRc5ErwsS/Ewa5E1yYdb3LaeQF1fMRo5QVoF/2Eqo=; b=RoicZqIBKSkJyEUtNsos0LZkUFRqTGXgwOG/+MTcdLtsxiH+jClUNsZiKVeKtkdVis raKdykBUgYZSXL9mjU4MQbVXJUftCAkWVXgZzeUYEpXNmwlXx0heArGBPLJN/q5SGcLl NkNZbz+DFb0YQw41wbXpahPxi9iQG8gM4nvaND2QRH5Oo/lk/7gPJ6V4789aXHpqh4uy CymEJyaYFAuLKQTD2dL03ObMQq4Hk/UbtKq7O2lUB6kABJD7ZbrjcmKgpGiQ2MfBE730 YShG8TMy+Ulgc3vc/9lyI+TijsdhSKkaAml7m/evj1VMIEcGTmSc7ImYeXihGNqQ+bYD HYrQ== X-Gm-Message-State: AOAM532eMh1UTsvMtmna0m2uLIOFeim4XJnDt1BnoxyI4xCi2T+vU/F5 wJuNrNdjQ4sfC8WBDEzZ3iEKMhXIepUYX05y X-Google-Smtp-Source: ABdhPJwFKOgmrHyRZaG28+KjMjeJzOmmK7My59a9ldaCf5d4L5gR2FEiUIJUarZVZmYysxSavslSHQ== X-Received: by 2002:adf:f189:: with SMTP id h9mr28151235wro.463.1638105904176; Sun, 28 Nov 2021 05:25:04 -0800 (PST) Received: from bismarck.berto.se (p54ac5892.dip0.t-ipconnect.de. [84.172.88.146]) by smtp.googlemail.com with ESMTPSA id bg34sm15911535wmb.47.2021.11.28.05.25.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 28 Nov 2021 05:25:03 -0800 (PST) From: =?utf-8?q?Niklas_S=C3=B6derlund?= To: Hans Verkuil , linux-media@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, =?utf-8?q?Niklas_S=C3=B6derlund?= Subject: [PATCH] media: rcar-vin: Do not hold the group lock when unregistering notifier Date: Sun, 28 Nov 2021 14:24:59 +0100 Message-Id: <20211128132459.142829-1-niklas.soderlund+renesas@ragnatech.se> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.4 (--) X-LSpam-Report: No, score=-2.4 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no There is no need to hold the group lock when unregistering the notifier, but doing so triggers a warning about a possible cyclic lock dependency. The lock warning cover the case where a subdevice is about to be bound to the notifier at the same time as it's unregistered. The locking for this scenario is handled in the v4l2-async framework so it's safe to remove the lock in the driver. This match the locking logic in the driver for when the notifier in question is registered. Signed-off-by: Niklas Söderlund --- drivers/media/platform/rcar-vin/rcar-core.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c index 1d92cc8ede8f8a3e..b58c8bbe1cf33908 100644 --- a/drivers/media/platform/rcar-vin/rcar-core.c +++ b/drivers/media/platform/rcar-vin/rcar-core.c @@ -349,12 +349,10 @@ static int rvin_group_parse_of(struct rvin_dev *vin, unsigned int port, static void rvin_group_notifier_cleanup(struct rvin_dev *vin) { - mutex_lock(&vin->group->lock); if (&vin->v4l2_dev == vin->group->notifier.v4l2_dev) { v4l2_async_nf_unregister(&vin->group->notifier); v4l2_async_nf_cleanup(&vin->group->notifier); } - mutex_unlock(&vin->group->lock); } static int rvin_group_notifier_init(struct rvin_dev *vin, unsigned int port,