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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 5E4BAC4338F for ; Tue, 24 Aug 2021 17:26:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 415E4610A7 for ; Tue, 24 Aug 2021 17:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240613AbhHXR1D convert rfc822-to-8bit (ORCPT ); Tue, 24 Aug 2021 13:27:03 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:58603 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240774AbhHXRWw (ORCPT ); Tue, 24 Aug 2021 13:22:52 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 0A9BF200003; Tue, 24 Aug 2021 17:22:04 +0000 (UTC) Date: Tue, 24 Aug 2021 19:22:03 +0200 From: Miquel Raynal To: Kestrel seventyfour Cc: Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mtd: rawnand: xway: No hardcoded ECC engine, use device tree setting Message-ID: <20210824192203.076df55e@xps13> In-Reply-To: References: <20210808072643.GA5084@ubuntu> <20210816093126.442f74a1@xps13> <20210819100334.6af2d86e@xps13> <20210823172413.0bc4ab3a@xps13> 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 Hello, Kestrel seventyfour wrote on Tue, 24 Aug 2021 09:15:49 +0200: > Hi Miquèl, > > Am Mo., 23. Aug. 2021 um 17:24 Uhr schrieb Miquel Raynal > : > > > > Hi Kestrel, > > > > Kestrel seventyfour wrote on Mon, 23 Aug > > 2021 13:19:43 +0200: > > > > > Hi Miquèl, > > > > > > Am Do., 19. Aug. 2021 um 10:03 Uhr schrieb Miquel Raynal > > > : > ... > > > > > > thank you for your response. > > > If I remove the nand-ecc-xxx properties in the device tree, the device with > > > the Toshiba NAND chip is working. However, the device with the Micron > > > NAND fails with NO ECC functions supplied; hardware ECC not possible, > > > seems to be at line 5367 or equivalent. > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_base.c#L5367 > > > > > > It looks like the micron nand driver supports on die only if its > > > specified int the > > > Device tree: > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_micron.c#L511 > > > The Micron NAND driver probably needs to set the ECC type to ON DIE if the > > > variable ondie contains the supported attribute?! > > > > You're right but I don't see any easy upstream-able solution here. > > Changing the behavior in the Xway driver would certainly break users, > > changing the behavior in the Micron driver would certainly break even > > more users. The root cause being an absence of proper description (the > > integration changed). Honestly I feel stuck, maybe you can try to > > register your device, if it fails, change the integration in the driver > > (to an ondie ecc engine) then retry? > > > > Thanks, > > Miquèl > > Do you think adding something like below at the following location > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/xway_nand.c#L223 > would be upstreamable (with or without device tree property?)? > > err = nand_scan(&data->chip, 1); > if (err /* && of_property_read_bool(np, "lantiq,retry-on-die") */) { > data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_DIE; > err = nand_scan(&data->chip, 1); > if (err) return err; > } > > It still throws the kernel warning on first try, but the second try then works. Can you please remind me what is xway/lantiq/your setup/how public it is/who's using this driver? Thanks, Miquèl