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 X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA2E5C432BE for ; Tue, 17 Aug 2021 10:07:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D039560F38 for ; Tue, 17 Aug 2021 10:07:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239563AbhHQKHg convert rfc822-to-8bit (ORCPT ); Tue, 17 Aug 2021 06:07:36 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:36325 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239303AbhHQKFE (ORCPT ); Tue, 17 Aug 2021 06:05:04 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 6A8D524000F; Tue, 17 Aug 2021 10:04:02 +0000 (UTC) Date: Tue, 17 Aug 2021 12:04:01 +0200 From: Miquel Raynal To: Zhihao Cheng Cc: , , , , , , Subject: Re: [PATCH v2] mtd: mtdconcat: Check existence of _read|_write from subdev'master device before assigning Message-ID: <20210817120401.1ccf98bd@xps13> In-Reply-To: <8b315831-84c5-38f3-d3b7-bb53f52c28b8@huawei.com> References: <20210817024552.1691649-1-chengzhihao1@huawei.com> <8b315831-84c5-38f3-d3b7-bb53f52c28b8@huawei.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Zhihao, Zhihao Cheng wrote on Tue, 17 Aug 2021 10:45:55 +0800: > 在 2021/8/17 10:45, Zhihao Cheng 写道: > Hi Miquel, > I found a better way to fix the "WARNING" on _read|_read_oob checking. Since sub-mtd device has been registered successfully, we can check against the existence of _read|_read_oob callbacks by subdev's master device. > BTW, fix missing space between the SHA1 and the subject suggested by Stephen. I am a bit lost, I need to see the big picture again. I will drop the current patches that applied, please resend the full series with a changelog. > > Since 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() as wrappers > > around mtd_{read,write}_oob()") don't allow _write|_read and > > _write_oob|_read_oob existing at the same time. We should check the , we > > existence of callbacks "_read and _write" from subdev's master device > > (We can trust master device since it has been registered) before > > assigning, otherwise following warning occurs while making > > concatenated device: > > > > WARNING: CPU: 2 PID: 6728 at drivers/mtd/mtdcore.c:595 > > add_mtd_device+0x7f/0x7b0 > > > > Fixes: 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() around ...") ^ Wrong commit message > > Signed-off-by: Zhihao Cheng > > --- Also, please shorten a bit the two commit titles, like: mtd: mtdconcat: Judge callback existence based on the master Finally, in the other patch, there is a typo in the example reproduce.c (combine misspelled). > > drivers/mtd/mtdconcat.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c > > index af51eee6b5e8..f685a581df48 100644 > > --- a/drivers/mtd/mtdconcat.c > > +++ b/drivers/mtd/mtdconcat.c > > @@ -694,6 +694,10 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c > > concat->mtd._block_markbad = concat_block_markbad; > > if (subdev_master->_panic_write) > > concat->mtd._panic_write = concat_panic_write; > > + if (subdev_master->_read) > > + concat->mtd._read = concat_read; > > + if (subdev_master->_write) > > + concat->mtd._write = concat_write; > > > concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks; > > > @@ -755,8 +759,6 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c > > concat->mtd.name = name; > > > concat->mtd._erase = concat_erase; > > - concat->mtd._read = concat_read; > > - concat->mtd._write = concat_write; > > concat->mtd._sync = concat_sync; > > concat->mtd._lock = concat_lock; > > concat->mtd._unlock = concat_unlock; > > Thanks, Miquèl