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 A4561C433EF for ; Wed, 20 Oct 2021 09:13:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80F386137C for ; Wed, 20 Oct 2021 09:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229809AbhJTJQI (ORCPT ); Wed, 20 Oct 2021 05:16:08 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:57902 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229503AbhJTJQH (ORCPT ); Wed, 20 Oct 2021 05:16:07 -0400 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 498E71F43FBF; Wed, 20 Oct 2021 10:13:52 +0100 (BST) Date: Wed, 20 Oct 2021 11:13:47 +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 v2 2/4] mtd: core: protect access to MTD devices while in suspend Message-ID: <20211020111347.627159a2@collabora.com> In-Reply-To: <20211020084534.2472305-3-sean@geanix.com> References: <20211020084534.2472305-1-sean@geanix.com> <20211020084534.2472305-3-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 Wed, 20 Oct 2021 10:45:32 +0200 Sean Nyekjaer wrote: > static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user) > @@ -1257,6 +1259,8 @@ int mtd_erase(struct mtd_info *mtd, sruct erase_info *instr) > > ledtrig_mtd_activity(); > > + mtd_start_access(master); > + > if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { > adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) * > master->erasesize; > @@ -1278,6 +1282,8 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) > } > } > > + mtd_end_access(master); > + The section covered in mtd_erase() is too broad. Put the start/end calls around the ->_erase() call. > return ret; > } > @@ -1576,7 +1604,6 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) > ret_code = mtd_read_oob_std(mtd, from, ops); > > mtd_update_ecc_stats(mtd, master, &old_stats); > - Unrelated line removal. Please drop this change. > /* > * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics > * similar to mtd->_read(), returning a non-negative integer > @@ -1615,7 +1642,9 @@ int mtd_write_oob(struct mtd_info *mtd, loff_t to, > if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) > return mtd_io_emulated_slc(mtd, to, false, ops); > > - return mtd_write_oob_std(mtd, to, ops); > + ret = mtd_write_oob_std(mtd, to, ops); > + > + return ret; Ditto, you can keep the 'return mtd_write_oob_std(mtd, to, ops);' here. > } > EXPORT_SYMBOL_GPL(mtd_write_oob); > +static inline void mtd_start_access(struct mtd_info *master) > +{ > + WARN_ON_ONCE(master != mtd_get_master(master)); > + > + /* > + * Don't take the suspend_lock on devices that don't > + * implement the suspend hook. Otherwise, lockdep will > + * complain about nested locks when trying to suspend MTD > + * partitions or MTD devices created by gluebi which are > + * backed by real devices. > + */ > + if (!master->_suspend) > + return; > + > + /* > + * Wait until the device is resumed. Should we have a > + * non-blocking mode here? > + */ > + while (1) { > + down_read(&master->master.suspend_lock); > + if (!master->master.suspended) > + return; > + > + up_read(&master->master.suspend_lock); > + wait_event(master->master.resume_wq, master->master.suspended == 0); Please keep the tests consistent: wait_event(master->master.resume_wq, !master->master.suspended); > + } > +} > +