From patchwork Mon Dec 5 08:24:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bayi Cheng X-Patchwork-Id: 13064257 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 0FBA8C47088 for ; Mon, 5 Dec 2022 08:24:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232072AbiLEIYn (ORCPT ); Mon, 5 Dec 2022 03:24:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231784AbiLEIYe (ORCPT ); Mon, 5 Dec 2022 03:24:34 -0500 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD2F0BF57; Mon, 5 Dec 2022 00:24:27 -0800 (PST) X-UUID: 90bceca878974e0b8639e97f93e0ebf7-20221205 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=GlJ2Pnimn4eRqc2TDacYNHE0ujFtrinL9YvZeTlViIw=; b=BDlmM6I1mOIfFxSsSzs8dOVF1XDyW56S3YOWCdWhzHOWGPCurZbCT8qWeDvvNJLXZBflGbuHMxi2uSSyKJ218JT9tXMlb6kAijT/2wG6glZHQt9OxJ3Vdm3fo2SBt+ZEo3AHqWT6PKZMuXbih4csbWfS6AzaPun5Qb6BcRTJRWE=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.14,REQID:88e325dd-963d-4116-92a1-eb5f3175ecf6,IP:0,U RL:0,TC:0,Content:-25,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-25 X-CID-META: VersionHash:dcaaed0,CLOUDID:847cb130-2938-482e-aafd-98d66723b8a9,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:0,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0 X-UUID: 90bceca878974e0b8639e97f93e0ebf7-20221205 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 535825791; Mon, 05 Dec 2022 16:24:23 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by mtkmbs11n2.mediatek.inc (172.21.101.187) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.15; Mon, 5 Dec 2022 16:24:21 +0800 Received: from localhost.localdomain (10.17.3.154) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.15 via Frontend Transport; Mon, 5 Dec 2022 16:24:21 +0800 From: Bayi Cheng To: Mark Brown , Matthias Brugger , Ikjoon Jang CC: , , , , Chuanhong Guo , , bayi cheng Subject: [PATCH v1] spi: spi-mtk-nor: Add recovery mechanism for dma read timeout Date: Mon, 5 Dec 2022 16:24:19 +0800 Message-ID: <20221205082419.29170-1-bayi.cheng@mediatek.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org From: bayi cheng The state machine of MTK spi nor controller may be disturbed by some glitch signals from the relevant BUS during dma read, Although the possibility of causing the dma read to fail is next to nothing, However, if error-handling is not implemented, which makes the feature somewhat risky. Add an error-handling mechanism here, reset the state machine and re-read the data when an error occurs. Signed-off-by: bayi cheng --- Change in v1: -Reset the state machine when dma read fails and read again. --- --- drivers/spi/spi-mtk-nor.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index d167699a1a96..c77d79da9a4c 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -80,6 +80,9 @@ #define MTK_NOR_REG_DMA_FADR 0x71c #define MTK_NOR_REG_DMA_DADR 0x720 #define MTK_NOR_REG_DMA_END_DADR 0x724 +#define MTK_NOR_REG_CG_DIS 0x728 +#define MTK_NOR_SFC_SW_RST BIT(2) + #define MTK_NOR_REG_DMA_DADR_HB 0x738 #define MTK_NOR_REG_DMA_END_DADR_HB 0x73c @@ -616,7 +619,18 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) mtk_nor_set_addr(sp, op); return mtk_nor_read_pio(sp, op); } else { - return mtk_nor_read_dma(sp, op); + ret = mtk_nor_read_dma(sp, op); + if (ret) { + dev_err(sp->dev, "try to read again\n"); + mtk_nor_rmw(sp, MTK_NOR_REG_CG_DIS, 0, MTK_NOR_SFC_SW_RST); + mb(); /* flush previous writes */ + mtk_nor_rmw(sp, MTK_NOR_REG_CG_DIS, MTK_NOR_SFC_SW_RST, 0); + mb(); /* flush previous writes */ + writel(MTK_NOR_ENABLE_SF_CMD, sp->base + MTK_NOR_REG_WP); + mtk_nor_setup_bus(sp, op); + ret = mtk_nor_read_dma(sp, op); + } + return ret; } }