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: 13064293 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 77FD0C4321E for ; Mon, 5 Dec 2022 09:06:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=6WuVEAEHQedzlJGVsFEL8/WOI0qNPRd3vv+HW1EGtBo=; b=ofcqewo7D4WYnP qcJCBSm4Qe67/T7TMysJRU2wnsHPgUhPHofXA0lp/O0t8xxmmjYFD4jE+7wlUVljF0c+FQHh+RoIk F/GdeG8IjMPIeSwYNRQaA2YckQI49Qxx1Wju2aEUJ0k9dDc/gRHm9vwzwr1ru6275ku5r4iTiMEXS 15wfC2DmRU2j6V85Gf7qyjYEnVSsG6AekowRfYL2cr1+SYcfUV8vbXVhgxsEGs4o7Nv9mgV+xEweu tPGGud/6/CIchEK+9a5LIPSzKPd9qiewpWJ7rFfPSa9e8+W5SyjQ05oPJFUS014VnWNyLNttvuXq9 Msjyy8R3J1Ga6NbLaTGA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p27PW-00Gn0f-QX; Mon, 05 Dec 2022 09:05:14 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p27PS-00Gmxc-Uj; Mon, 05 Dec 2022 09:05:12 +0000 X-UUID: eee61ffd911f431f839ccad6c576c03e-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:bfe9dfe2-ad5a-4857-921c-e1e35d839b4d,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:aad5dabc-3f71-4801-a1a6-1117dd275996,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: eee61ffd911f431f839ccad6c576c03e-20221205 Received: from mtkmbs11n1.mediatek.inc [(172.21.101.185)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 564790515; Mon, 05 Dec 2022 02:04:57 -0700 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221205_010511_019274_CBF7D95D X-CRM114-Status: GOOD ( 13.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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; } }