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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 CAC36C43381 for ; Fri, 15 Feb 2019 09:02:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81A7321925 for ; Fri, 15 Feb 2019 09:02:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="M06tQnzm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391957AbfBOJCN (ORCPT ); Fri, 15 Feb 2019 04:02:13 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:35745 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732672AbfBOJCL (ORCPT ); Fri, 15 Feb 2019 04:02:11 -0500 Received: by mail-pf1-f196.google.com with SMTP id j5so35213pfa.2 for ; Fri, 15 Feb 2019 01:02:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id; bh=TKEr6BQfPYwpZOOmXDLLiGCXvoI2GmC6CPcG6Delj7k=; b=M06tQnzmpEvPURrsn18wmE1G0bf8j/j3E4/gaRn5UHdWAIszU5S/8BRF4bn0GNtXSe r7t1bSEpPbePPUAaBWw95Kui9EIi7UJTA81Di6i6f5bxLCXBdflLoBmKbdqrWgc+DwRL gE2EemCnKz5LtwY05osXbp7gG2eB8OesL0+Ec= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=TKEr6BQfPYwpZOOmXDLLiGCXvoI2GmC6CPcG6Delj7k=; b=OOQNKskcudAgHTyjKBeatO3L+E0YBF3qqnBnYWQpXD/31LaHvo9PTVV2PmjQbeht4J cg3209J1ODZi+dhaowxQU5p/D6TfNAOUvYw2slhWWEQTLw9EGMms7/KHxrTJj2v8WgRz uPefFvZ6ge/D7O3dLHHiN2Ybwxn0nPlPayEP+/Zf+MX/r3YzXp1dnkDToa5HP1PxHhF4 RuDsBYoraThdz0+htCysxmG1fRfAmRZk2ZkMSr0NNjoF+KiqkFRco9cE1XCoIiEz8ToA h5v3wNvJJ58QRplyRI1QXLTPmsw0tv6HBZeO1KYvshRDAoeb4ezOTQv1EBeOwjtuO8XI gfiQ== X-Gm-Message-State: AHQUAuZ6tlpAFTMB2of0eQ9aTjtubpxqRKz3XrQj0gR6skuOEJp2YDaL wbW4n6yxcKN6fKSO0gq6rEDskA== X-Google-Smtp-Source: AHgI3IZ+IPALVVKhe1XQ2ry7m3Jzss69II/WcqBU5mzDNdUy2gIbEPcfg4GYGt2NpDsJktpgvm9zaw== X-Received: by 2002:a65:6219:: with SMTP id d25mr4392407pgv.18.1550221330954; Fri, 15 Feb 2019 01:02:10 -0800 (PST) Received: from hsinyi-z840.tpe.corp.google.com ([2401:fa00:1:10:b852:bd51:9305:4261]) by smtp.gmail.com with ESMTPSA id z67sm9012653pfd.188.2019.02.15.01.02.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 15 Feb 2019 01:02:10 -0800 (PST) From: Hsin-Yi Wang To: linux-arm-kernel@lists.infradead.org Cc: Matthias Brugger , Wolfram Sang , Jun Gao , Hsin-Yi Wang , Ryder Lee , linux-i2c@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] i2c: mediatek: modify threshold passed to i2c_get_dma_safe_msg_buf() Date: Fri, 15 Feb 2019 17:02:02 +0800 Message-Id: <20190215090202.157100-1-hsinyi@chromium.org> X-Mailer: git-send-email 2.18.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org i2c_get_dma_safe_msg_buf() allocates space based on msg->len. If threshold is 0 and msg->len is also 0, function makes zero-length allocation, which returns a special ZERO_SIZE_PTR instead of a NULL pointer, and this will cause later code to fail. Modify the threshold to > 0 so the function returns NULL pointer. Fixes: fc66b39fe36a ("i2c: mediatek: Use DMA safe buffers for i2c transactions") Signed-off-by: Hsin-Yi Wang --- drivers/i2c/busses/i2c-mt65xx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index a74ef76705e0..2bb4d20ead32 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -503,7 +503,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON); - dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_rd_buf) return -ENOMEM; @@ -526,7 +526,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON); - dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_wr_buf) return -ENOMEM; @@ -549,7 +549,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON); - dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_wr_buf) return -ENOMEM; @@ -561,7 +561,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, return -ENOMEM; } - dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 0); + dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1); if (!dma_rd_buf) { dma_unmap_single(i2c->dev, wpaddr, msgs->len, DMA_TO_DEVICE); -- 2.18.1