From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AAC2C433EF for ; Mon, 1 Nov 2021 07:47:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF65E60EFF for ; Mon, 1 Nov 2021 07:47:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231271AbhKAHtj (ORCPT ); Mon, 1 Nov 2021 03:49:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230312AbhKAHte (ORCPT ); Mon, 1 Nov 2021 03:49:34 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9109DC061714 for ; Mon, 1 Nov 2021 00:47:01 -0700 (PDT) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 1AEFA1F4369A; Mon, 1 Nov 2021 07:47:00 +0000 (GMT) Date: Mon, 1 Nov 2021 08:46:52 +0100 From: Boris Brezillon To: Sean Nyekjaer Cc: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/4] mtd: core: protect access to mtd devices while in suspend Message-ID: <20211101084652.0fe6272f@collabora.com> In-Reply-To: <20211026055551.3053598-1-sean@geanix.com> References: <20211026055551.3053598-1-sean@geanix.com> Organization: Collabora X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 26 Oct 2021 07:55:47 +0200 Sean Nyekjaer wrote: > Follow-up on discussion in: > https://lkml.org/lkml/2021/10/4/41 > https://lkml.org/lkml/2021/10/11/435 > > Changes since v3: > - edited commit msg and author for mtdconcat patch > > Changes since v2: > - added signoff's to patch from Boris > - removed accidential line break > - kept tests consistent: master->master.suspended == 0 -> !master->master.suspended > - added comments to mtdconcat patch > - moved mtdconcat before ('mtd: core: protect access to MTD devices while in suspend') > > Changes since v1: > - removed __mtd_suspend/__mtd_resume functions as they are not used by > mtdconcat anymore. > - only master mtd_info is used for mtd_{start,end}_access(). Warn if we > got mtd's. > - added Boris patch for using uninitialized _suspend/_resume hooks when > bbt scanning > - mtdconcat uses device _suspend/_resume hooks > - I don't really like the macro proposal from Boris > mtd_no_suspend_void_call()/mtd_no_suspend_ret_call() I think they > make the code complex to read and the macro's doesn't fit every > where anyway... > > Changes since from rfc v1/v2: > - added access protection for all device access hooks in mtd_info. > - added Suggested-by to [1/3] patch. > - removed refereces to commit ef347c0cfd61 ("mtd: rawnand: gpmi: Implement exec_op") > from commit msg as commit 013e6292aaf5 ("mtd: rawnand: Simplify the locking") is > to be blamed. > - tested on a kernel with LOCKDEP enabled. > > Boris Brezillon (2): > mtd: rawnand: nand_bbt: hide suspend/resume hooks while scanning bbt > mtd: mtdconcat: don't use mtd_{suspend,resume}() > > Sean Nyekjaer (2): > mtd: core: protect access to MTD devices while in suspend > mtd: rawnand: remove suspended check Looks good overall (after fixing the minor things I pointed out, of course), but I'd recommend applying this series to mtd-next just after -rc1 is out so you get a chance to detect regressions before it's merged in Linus' tree. I fear this unconditional blocking on suspended device will lead to unexpected deadlocks (see my comment on panic writes)... > > drivers/mtd/mtdconcat.c | 15 +++- > drivers/mtd/mtdcore.c | 124 +++++++++++++++++++++++++++---- > drivers/mtd/nand/raw/nand_base.c | 52 ++++--------- > drivers/mtd/nand/raw/nand_bbt.c | 28 ++++++- > include/linux/mtd/mtd.h | 81 ++++++++++++++++---- > include/linux/mtd/rawnand.h | 5 +- > 6 files changed, 230 insertions(+), 75 deletions(-) >