From patchwork Thu May 6 19:18:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pratyush Yadav X-Patchwork-Id: 431972 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 DC561C433ED for ; Thu, 6 May 2021 19:19:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8D4E61107 for ; Thu, 6 May 2021 19:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235587AbhEFTUA (ORCPT ); Thu, 6 May 2021 15:20:00 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:47058 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235588AbhEFTT7 (ORCPT ); Thu, 6 May 2021 15:19:59 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 146JIrtm095439; Thu, 6 May 2021 14:18:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1620328733; bh=8be/0Af1IpsSbPbMx0rjRmaqUa0F13Ayu7NXc7jIJ5U=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=fXEfgEIO/PaTEximsML7s0b3WQLojA5BosbU+/BmtezABdJ1Bd68BZJTkenl6BMWy +Tqiu8duTAJpOimBls2YKZ07yUUP7yS1+Fmr5hrdJp3VGU+Fsd7E4pgkdaG/3ieQQT 2ElzA1nVflaK+EEM7lt78lVe1xXw0vwuwE/rWpIY= Received: from DFLE108.ent.ti.com (dfle108.ent.ti.com [10.64.6.29]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 146JIre1016678 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 6 May 2021 14:18:53 -0500 Received: from DFLE110.ent.ti.com (10.64.6.31) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 6 May 2021 14:18:53 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DFLE110.ent.ti.com (10.64.6.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2 via Frontend Transport; Thu, 6 May 2021 14:18:53 -0500 Received: from pratyush-OptiPlex-790.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 146JIUNI026052; Thu, 6 May 2021 14:18:50 -0500 From: Pratyush Yadav To: Tudor Ambarus , Michael Walle , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mark Brown , , , CC: Pratyush Yadav Subject: [PATCH 6/6] mtd: spi-nor: core; avoid odd length/address writes in 8D-8D-8D mode Date: Fri, 7 May 2021 00:48:29 +0530 Message-ID: <20210506191829.8271-7-p.yadav@ti.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210506191829.8271-1-p.yadav@ti.com> References: <20210506191829.8271-1-p.yadav@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Octal DTR capable flashes like Micron Xcella the writes cannot start or end at an odd address in Octal DTR mode. Extra 0xff bytes need to be appended or prepended to make sure the start address and end address are even. 0xff is used because on NOR flashes a program operation can only flip bits from 1 to 0, not the other way round. 0 to 1 flip needs to happen via erases. Signed-off-by: Pratyush Yadav --- drivers/mtd/spi-nor/core.c | 72 +++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 3d66cc34af4d..265d8b25fc7f 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2022,6 +2022,71 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len, return ret; } +/* + * On Octal DTR capable flashes like Micron Xcella the writes cannot start or + * end at an odd address in Octal DTR mode. Extra 0xff bytes need to be appended + * or prepended to make sure the start address and end address are even. 0xff is + * used because on NOR flashes a program operation can only flip bits from 1 to + * 0, not the other way round. 0 to 1 flip needs to happen via erases. + */ +static int spi_nor_octal_dtr_write(struct spi_nor *nor, loff_t to, size_t len, + const u8 *buf) +{ + u8 *tmp_buf; + size_t bytes_written; + loff_t start, end; + int ret; + + if (IS_ALIGNED(to, 2) && IS_ALIGNED(len, 2)) + return spi_nor_write_data(nor, to, len, buf); + + tmp_buf = kmalloc(nor->page_size, GFP_KERNEL); + if (!tmp_buf) + return -ENOMEM; + + memset(tmp_buf, 0xff, nor->page_size); + + start = round_down(to, 2); + end = round_up(to + len, 2); + + memcpy(tmp_buf + (to - start), buf, len); + + ret = spi_nor_write_data(nor, start, end - start, tmp_buf); + if (ret == 0) { + ret = -EIO; + goto out; + } + if (ret < 0) + goto out; + + /* + * More bytes are written than actually requested, but that number can't + * be reported to the calling function or it will confuse its + * calculations. Calculate how many of the _requested_ bytes were + * written. + */ + bytes_written = ret; + + if (to != start) + ret -= to - start; + + /* + * Only account for extra bytes at the end if they were actually + * written. For example, if for some reason the controller could only + * complete a partial write then the adjustment for the extra bytes at + * the end is not needed. + */ + if (start + bytes_written == end) + ret -= end - (to + len); + + if (ret < 0) + ret = -EIO; + +out: + kfree(tmp_buf); + return ret; +} + /* * Write an address range to the nor chip. Data must be written in * FLASH_PAGESIZE chunks. The address range may be any size provided @@ -2066,7 +2131,12 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, if (ret) goto write_err; - ret = spi_nor_write_data(nor, addr, page_remain, buf + i); + if (nor->write_proto == SNOR_PROTO_8_8_8_DTR) + ret = spi_nor_octal_dtr_write(nor, addr, page_remain, + buf + i); + else + ret = spi_nor_write_data(nor, addr, page_remain, + buf + i); if (ret < 0) goto write_err; written = ret;