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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDB77C433F5 for ; Mon, 21 Mar 2022 17:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350073AbiCURod (ORCPT ); Mon, 21 Mar 2022 13:44:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349403AbiCURob (ORCPT ); Mon, 21 Mar 2022 13:44:31 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2CA5DFF for ; Mon, 21 Mar 2022 10:43:01 -0700 (PDT) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 22LHgqcv000374; Mon, 21 Mar 2022 12:42:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1647884572; bh=w1nssn3aZv3EvnBbeSHoVlZA7OBBWbfhVwK6ZRd350A=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=nC62Q8oW8++CQMPC1p4CAkSWBrjQdp6p80If1ZrYwtWvySL+YxejaOM9VhYr/Atdd vMOLTmbWtA6A0TltvdlCHYnj2RV41Pb/Bywd+KgUOVxuab4liQTZpbIHFgcpxeKvYr oRYFYjCzxVRxsBqx8hbzHp73HEYp8edhuQ7mdkL4= Received: from DFLE113.ent.ti.com (dfle113.ent.ti.com [10.64.6.34]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 22LHgqJk027761 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 21 Mar 2022 12:42:52 -0500 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Mon, 21 Mar 2022 12:42:52 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Mon, 21 Mar 2022 12:42:52 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 22LHgpei021588; Mon, 21 Mar 2022 12:42:52 -0500 Date: Mon, 21 Mar 2022 23:12:51 +0530 From: Pratyush Yadav To: CC: , , , , , , Subject: Re: [PATCH v2 3/8] mtd: spi-nor: core: Use auto-detection only once Message-ID: <20220321174251.ehhobu26tgoxrbps@ti.com> References: <20220228111712.111737-1-tudor.ambarus@microchip.com> <20220228111712.111737-4-tudor.ambarus@microchip.com> <20220321121455.bpql7x4ebhq7s36l@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/03/22 12:50PM, Tudor.Ambarus@microchip.com wrote: > On 3/21/22 14:14, Pratyush Yadav wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > > On 28/02/22 01:17PM, Tudor Ambarus wrote: > >> In case spi_nor_match_name() returned NULL, the auto detection was > >> issued twice. There's no reason to try to detect the same chip twice, > >> do the auto detection only once. > >> > >> Signed-off-by: Tudor Ambarus > >> --- > >> drivers/mtd/spi-nor/core.c | 10 ++++++---- > >> 1 file changed, 6 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > >> index f87cb7d3daab..b1d6fa65417d 100644 > >> --- a/drivers/mtd/spi-nor/core.c > >> +++ b/drivers/mtd/spi-nor/core.c > >> @@ -2894,13 +2894,15 @@ static const struct flash_info *spi_nor_match_name(struct spi_nor *nor, > >> static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor, > >> const char *name) > >> { > >> - const struct flash_info *info = NULL; > >> + const struct flash_info *info = NULL, *detected_info = NULL; > >> > >> if (name) > >> info = spi_nor_match_name(nor, name); > >> /* Try to auto-detect if chip name wasn't specified or not found */ > >> - if (!info) > >> - info = spi_nor_read_id(nor); > >> + if (!info) { > >> + detected_info = spi_nor_read_id(nor); > >> + info = detected_info; > >> + } > >> if (IS_ERR_OR_NULL(info)) > >> return ERR_PTR(-ENOENT); > >> > >> @@ -2908,7 +2910,7 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor, > >> * If caller has specified name of flash model that can normally be > >> * detected using JEDEC, let's verify it. > >> */ > >> - if (name && info->id_len) { > >> + if (name && !detected_info && info->id_len) { > >> const struct flash_info *jinfo; > >> > >> jinfo = spi_nor_read_id(nor); > > > > I think the flow can be a little bit better. How about: > > > > if (name) > > info = spi_nor_match_name(); > > > > if (!info) { > > info = spi_nor_read_id(); > > if (IS_ERR_OR_NULL(info)) > > return ERR_PTR(-ENOENT); > > > > return info; > > } > > Here we miss the IS_ERR check in case info is retrieved with spi_nor_match_name(). > Do you expect spi_nor_match_name() to ever return an error? As it is now it doesn't. > I'm fine either way. In case you want me to follow your suggestion, give me a sign > and I'll make a dedicated patch to move the IS_ERR_OR_NULL check. Will add your > Suggested-by tag. I think it should be safe to assume it won't ever return an error since all it does is iterate over an array that is always present. I don't see that changing in the foreseeable future either. So I think not having the IS_ERR check is fine. -- Regards, Pratyush Yadav Texas Instruments Inc.