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 CDDFFC4332F for ; Mon, 11 Oct 2021 13:59:04 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 972FA61211 for ; Mon, 11 Oct 2021 13:59:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 972FA61211 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Dvz/bCCE/cvDIMUMA/a06jtw7NWwPytMWo/P33BHM3k=; b=3AkvdyivQATJPL gKZKsB/EmB3+k6uR775oKfWrPkOSZZqfpEJ1idj/Os+1ay3qxZpPtLsWEeZYYhAYXCPS1gpTlTA0e xXS84oZbfBTdvKo0kPGfv7IBauz3jZOP2smr8Vg9knM5pAguCHtzevL3ZetRTnbJ9A55k6M9kAr4Q fuPTjLVcifIfqTFDUuKJkM+528BSQ+l68I2apq4p0dJLPldL6/y99qn1CeoKUbItReNyBUcPhMb2b 1Oj9jqZi/yo3BQd3+287OygKEBMmkCfTKlq6fw/Bospnw8/U0CiNGaWXfsKigWhwTHr3wDmLqxcmm NrKkwew3Q+gjZ7UD0vlQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mZvoi-009gRv-ON; Mon, 11 Oct 2021 13:58:12 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mZvog-009gR6-Ga for linux-mtd@lists.infradead.org; Mon, 11 Oct 2021 13:58:11 +0000 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 F04FC1F42D7B; Mon, 11 Oct 2021 14:58:08 +0100 (BST) Date: Mon, 11 Oct 2021 15:58:05 +0200 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 3/3] mtd: mtdconcat: add suspend lock handling Message-ID: <20211011155805.7793ad21@collabora.com> In-Reply-To: <20211011115253.38497-4-sean@geanix.com> References: <20211011115253.38497-1-sean@geanix.com> <20211011115253.38497-4-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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211011_065810_714796_16F37F50 X-CRM114-Status: GOOD ( 22.01 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Mon, 11 Oct 2021 13:52:53 +0200 Sean Nyekjaer wrote: > Use new suspend lock handling for this special case for concatenated > MTD devices. > > Fixes: 013e6292aaf5 ("mtd: rawnand: Simplify the locking") > Signed-off-by: Sean Nyekjaer > --- > drivers/mtd/mtdconcat.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c > index f685a581df48..c497c851481f 100644 > --- a/drivers/mtd/mtdconcat.c > +++ b/drivers/mtd/mtdconcat.c > @@ -561,25 +561,32 @@ static void concat_sync(struct mtd_info *mtd) > > static int concat_suspend(struct mtd_info *mtd) > { > + struct mtd_info *master = mtd_get_master(mtd); > struct mtd_concat *concat = CONCAT(mtd); > int i, rc = 0; > > for (i = 0; i < concat->num_subdev; i++) { > struct mtd_info *subdev = concat->subdev[i]; > - if ((rc = mtd_suspend(subdev)) < 0) > + > + down_write(&master->master.suspend_lock); You should definitely not take the concat lock here, the framework does it for you, so all you'll get is a deadlock. > + if ((rc = __mtd_suspend(subdev)) < 0) > return rc; You're returning with the lock held => DEADLOCK next time you try to acquire it. Anyway, as mentioned in my review of patch 1, I'd go for this ad-hoc solution: for (i = 0; i < concat->num_subdev; i++) { rc = subdev->_suspend ? subdev->_suspend(subdev) : 0; if (rc < 0) return rc; } return 0; > + up_write(&master->master.suspend_lock); > } > return rc; > } > > static void concat_resume(struct mtd_info *mtd) > { > + struct mtd_info *master = mtd_get_master(mtd); > struct mtd_concat *concat = CONCAT(mtd); > int i; > > for (i = 0; i < concat->num_subdev; i++) { > struct mtd_info *subdev = concat->subdev[i]; > - mtd_resume(subdev); > + down_write(&master->master.suspend_lock); > + __mtd_resume(subdev); > + up_write(&master->master.suspend_lock); > } No down/up_write() needed: for (i = 0; i < concat->num_subdev; i++) { struct mtd_info *subdev = concat->subdev[i]; if (subdev->_resume) subdev->_resume(subdev); } > } > ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/