From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 1F7C979DDA; Thu, 29 Feb 2024 10:55:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709204144; cv=none; b=RXRCn/fliMovFHaV1chXOGpPdjfdIskgfWURXbcjsLs2C85mRhJReCsbDk6b2cDqwgg3snlNSaukukKhd0oGP6bYCJuMVJxvRZlUHFLcNwdUc3YDKB9ng46YvVtvhEd575TrZIjXMLm9OtlWxBaEJRoVCvK+ot1RcL220FhjdjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709204144; c=relaxed/simple; bh=uJQ8oK6S3btZM/i+xqMBD+VnKIFGNlckNP4cfaBVpp8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Lmyn20S4nCfH9h/gOxk3/Rd4nsvbkCJpu+L5hm4KNnKcouaP4zTHr5gj6t0wSpJ61GpK3PIApqZj+NW7lbWOL9QCFm2pnWYraZMWTxDEeepV4I7mMt0xpjI/X61E3rotd3NofccZuXFvuiL0RT3jWghk6eQE3H1gKMJyO/tXs5w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=X29181Pg; arc=none smtp.client-ip=217.70.183.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="X29181Pg" Received: by mail.gandi.net (Postfix) with ESMTPSA id 5A92FFF809; Thu, 29 Feb 2024 10:55:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1709204140; 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=ucmCXKr9aC1Z8X3a+6gOaQampla6gbJJBtAdPFqD47o=; b=X29181PgT3vCMk+kh1MSYsbzKUVA4SU2MSz62Y9uwO2DfTgwj92cYZ4UJKpoAudrvKwn3W ZS+7H74PBUwe3jysNFI8q0sdKZBIsv5YzVwXN3jMcvzFDnZKjBzPDM7lNQLhWPdO56hFau JY/r0WbXSzxd86RvGYvpBY+7aioaKto5lNzm8yLUoNm9EC4xB4uMRY/dgyOACGEfiTXZY0 pb30wl/Tr0bMXusNsuWgiFmsGFS4drC3yLIIuXjV9JQIYzzlkNW8DFaYHE7MJ4JFpv7eaI BLfj0gE0dBUrcnGsBx+C2NtqYJjpfzXEXuZYcur7siSHAsjYaBUiKDvCbZJKsA== Date: Thu, 29 Feb 2024 11:55:38 +0100 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 , Luca Ceresoli , Nuno Sa , Thomas Petazzoni Subject: Re: [PATCH v2 0/2] Synchronize DT overlay removal with devlink removals Message-ID: <20240229115538.7d2f5a35@bootlin.com> In-Reply-To: <20240229083953.607569-1-herve.codina@bootlin.com> References: <20240229083953.607569-1-herve.codina@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-redhat-linux-gnu) 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 All, I did a mistake in this series. As noted by Nuno, the device.h include is missing in patch 2 and so the patch 2 doesn't compile :( A v3 is already sent fixing my missing device.h mistake. https://lore.kernel.org/all/20240229105204.720717-1-herve.codina@bootlin.com/ Sorry for this error. Best regards, Hervé On Thu, 29 Feb 2024 09:39:40 +0100 Herve Codina wrote: > 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). > > Compared to the previous iteration: > https://lore.kernel.org/linux-kernel/20231130174126.688486-1-herve.codina@bootlin.com/ > this v2 series mainly: > - Renames the workqueue used. > - Calls device_link_wait_removal() a bit later to handle cases reported > by Luca [1] and Nuno [2]. > [1]: https://lore.kernel.org/all/20231220181627.341e8789@booty/ > [2]: https://lore.kernel.org/all/20240205-fix-device-links-overlays-v2-2-5344f8c79d57@analog.com/ > > Best regards, > Hervé > > Changes v1 -> v2 > - Patch 1 > Rename the workqueue to 'device_link_wq' > Add 'Fixes' tag and Cc stable > > - Patch 2 > Add device.h inclusion. > Call device_link_wait_removal() later in the overlay removal > sequence (i.e. in free_overlay_changeset() function). > Drop of_mutex lock while calling device_link_wait_removal(). > Add 'Fixes' tag and Cc stable > > 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 | 9 ++++++++- > include/linux/device.h | 1 + > 3 files changed, 32 insertions(+), 4 deletions(-) >