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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 9F0C5C6778A for ; Sun, 22 Jul 2018 08:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 505702086A for ; Sun, 22 Jul 2018 08:52:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 505702086A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728143AbeGVJpP (ORCPT ); Sun, 22 Jul 2018 05:45:15 -0400 Received: from mail.bootlin.com ([62.4.15.54]:59212 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727962AbeGVJpO (ORCPT ); Sun, 22 Jul 2018 05:45:14 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 02F06207AD; Sun, 22 Jul 2018 10:49:15 +0200 (CEST) Received: from bbrezillon (unknown [37.173.20.83]) by mail.bootlin.com (Postfix) with ESMTPSA id 0AD7320737; Sun, 22 Jul 2018 10:49:12 +0200 (CEST) Date: Sun, 22 Jul 2018 10:49:12 +0200 From: Boris Brezillon To: Miquel Raynal Cc: Wenyou Yang , Josh Wu , Tudor Ambarus , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Nicolas Ferre , Alexandre Belloni , Kamal Dasu , Masahiro Yamada , Han Xu , Harvey Hunt , Vladimir Zapolskiy , Sylvain Lemieux , Xiaolei Li , Matthias Brugger , Maxime Ripard , Chen-Yu Tsai , Marc Gonzalez , Mans Rullgard , Stefan Agner , linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-mediatek@lists.infradead.org Subject: Re: [PATCH v4 28/35] mtd: rawnand: allow exiting immediately nand_scan_ident() Message-ID: <20180722104912.77e81f8d@bbrezillon> In-Reply-To: <20180720151527.16038-29-miquel.raynal@bootlin.com> References: <20180720151527.16038-1-miquel.raynal@bootlin.com> <20180720151527.16038-29-miquel.raynal@bootlin.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Jul 2018 17:15:20 +0200 Miquel Raynal wrote: > Some driver (eg. docg4) will need to handle themselves the > identification phase. As part of the migration to use nand_scan() > everywhere (which will unconditionnaly call nand_scan_ident()), we add > a condition at the start of nand_scan_ident() to just "do nothing" if > the maxchips parameters is zero, meaning that the driver does not want > the core to handle this phase. > > Signed-off-by: Miquel Raynal > --- > drivers/mtd/nand/raw/nand_base.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c > index dea41fa25be1..e7f135c100c2 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -5926,7 +5926,7 @@ static int nand_dt_init(struct nand_chip *chip) > /** > * nand_scan_ident - [NAND Interface] Scan for the NAND device > * @mtd: MTD device structure > - * @maxchips: number of chips to scan for > + * @maxchips: number of chips to scan for, returns immediately if 0 > * @table: alternative NAND ID table > * > * This is the first phase of the normal nand_scan() function. It reads the > @@ -5940,6 +5940,14 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips, > struct nand_chip *chip = mtd_to_nand(mtd); > int ret; > > + /* > + * If the number of chips to scan for is null, just return silently. ^ zero > + * This is for specific drivers that must handle this part of the > + * probe process themselves (e.g docg4). > + */ I think that description of the special case maxchips == 0 should be placed in the kernel doc header. > + if (!maxchips) > + return 0; Can we move this check in nand_scan_with_ids()? > + > /* Enforce the right timings for reset/detection */ > onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0); >