From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="YoKRgwhA" Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::228]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B547131; Thu, 30 Nov 2023 09:41:31 -0800 (PST) Received: by mail.gandi.net (Postfix) with ESMTPA id 96FB71BF204; Thu, 30 Nov 2023 17:41:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1701366090; 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; bh=yvt6xwQtma5BgVNgEWdmqb5WwlVdI81bFmTFIjob+Mc=; b=YoKRgwhAp78MJzd93oCesNXjw7Ycio+S7kvwK1i6xHARYrwsm3Wa6UMaMTzGYHM8bjZoWR vaHXZBcUrq/VEkYwbGp3kQyUbUGz+EuKc2OEqsZQEITDz+ovTU3Qk6lmBb8NzvOyCEzm6E RFWjvcAbKVUmLyk/eJJ31bDYUqdblg+w5aQPk+WE94qXsxAT/ABy63L31xjvdwnbtOEstw Gulzu+gVIApBU7xqWc65mKE10z1INu57LVSxd3I2penHHX204ZOcvU8VHNC9ybVkDedMJg N9pz+nzZ8VUMA9UROmEldwIbDjtSo6GR5bTN7ODHKx4Cc28ukjYUNszj73f6uQ== From: Herve Codina To: Greg Kroah-Hartman , "Rafael J. Wysocki" , Rob Herring , Frank Rowand Cc: Lizhi Hou , Max Zhen , Sonal Santan , Stefano Stabellini , Jonathan Cameron , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Allan Nielsen , Horatiu Vultur , Steen Hegelund , Thomas Petazzoni , Herve Codina Subject: [PATCH 0/2] Synchronize DT overlay removal with devlink removals Date: Thu, 30 Nov 2023 18:41:07 +0100 Message-ID: <20231130174126.688486-1-herve.codina@bootlin.com> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-GND-Sasl: herve.codina@bootlin.com Hi, In the following sequence: of_platform_depopulate(); /* Remove devices from a DT overlay node */ of_overlay_remove(); /* Remove the DT overlay node itself */ Some warnings are raised by __of_changeset_entry_destroy() which was called from of_overlay_remove(): ERROR: memory leak, expected refcount 1 instead of 2 ... The issue is that, during the device devlink removals triggered from the of_platform_depopulate(), jobs are put in a workqueue. These jobs drop the reference to the devices. When a device is no more referenced (refcount == 0), it is released and the reference to its of_node is dropped by a call to of_node_put(). These operations are fully correct except that, because of the workqueue, they are done asynchronously with respect to function calls. In the sequence provided, the jobs are run too late, after the call to __of_changeset_entry_destroy() and so a missing of_node_put() call is detected by __of_changeset_entry_destroy(). This series fixes this issue introducing device_link_wait_removal() in order to wait for the end of jobs execution (patch 1) and using this function to synchronize the overlay removal with the end of jobs execution (patch 2). Best regards, Hervé Herve Codina (2): driver core: Introduce device_link_wait_removal() of: overlay: Synchronize of_overlay_remove() with the devlink removals drivers/base/core.c | 26 +++++++++++++++++++++++--- drivers/of/overlay.c | 6 ++++++ include/linux/device.h | 1 + 3 files changed, 30 insertions(+), 3 deletions(-) -- 2.42.0