From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bitan Biswas Subject: [PATCH V5 6/7] i2c: tegra: fix PIO rx/tx residual transfer check Date: Tue, 11 Jun 2019 03:51:13 -0700 Message-ID: <1560250274-18499-6-git-send-email-bbiswas@nvidia.com> References: <1560250274-18499-1-git-send-email-bbiswas@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1560250274-18499-1-git-send-email-bbiswas@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Laxman Dewangan , Thierry Reding , Jonathan Hunter , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Rosin , Wolfram Sang , Dmitry Osipenko Cc: Shardar Mohammed , Sowjanya Komatineni , Mantravadi Karthik , Bitan Biswas List-Id: linux-tegra@vger.kernel.org Fix expression for residual bytes(less than word) transfer in I2C PIO mode RX/TX. Signed-off-by: Bitan Biswas --- drivers/i2c/busses/i2c-tegra.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 4dfb4c1..0596c12 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -514,7 +514,8 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) * If there is a partial word at the end of buf, handle it manually to * prevent overwriting past the end of buf */ - if (rx_fifo_avail > 0 && buf_remaining > 0) { + if (rx_fifo_avail > 0 && + (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) { BUG_ON(buf_remaining > 3); val = i2c_readl(i2c_dev, I2C_RX_FIFO); val = cpu_to_le32(val); @@ -557,11 +558,10 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) words_to_transfer = tx_fifo_avail; /* - * Update state before writing to FIFO. If this casues us + * Update state before writing to FIFO. If this causes us * to finish writing all bytes (AKA buf_remaining goes to 0) we * have a potential for an interrupt (PACKET_XFER_COMPLETE is - * not maskable). We need to make sure that the isr sees - * buf_remaining as 0 and doesn't call us back re-entrantly. + * not maskable). */ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD; tx_fifo_avail -= words_to_transfer; @@ -580,7 +580,8 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) * prevent reading past the end of buf, which could cross a page * boundary and fault. */ - if (tx_fifo_avail > 0 && buf_remaining > 0) { + if (tx_fifo_avail > 0 && + (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) { BUG_ON(buf_remaining > 3); memcpy(&val, buf, buf_remaining); val = le32_to_cpu(val); -- 2.7.4 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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 DC596C4321A for ; Tue, 11 Jun 2019 10:54:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B13C320657 for ; Tue, 11 Jun 2019 10:54:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="BwbdazJU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388113AbfFKKyt (ORCPT ); Tue, 11 Jun 2019 06:54:49 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:3990 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387978AbfFKKys (ORCPT ); Tue, 11 Jun 2019 06:54:48 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 11 Jun 2019 03:54:45 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 11 Jun 2019 03:54:47 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 11 Jun 2019 03:54:47 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 11 Jun 2019 10:53:34 +0000 Received: from hqnvemgw02.nvidia.com (172.16.227.111) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 11 Jun 2019 10:51:37 +0000 Received: from dhcp-10-19-65-14.client.nvidia.com (Not Verified[10.19.65.14]) by hqnvemgw02.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Tue, 11 Jun 2019 03:51:37 -0700 From: Bitan Biswas To: Laxman Dewangan , Thierry Reding , Jonathan Hunter , , , , Peter Rosin , Wolfram Sang , Dmitry Osipenko CC: Shardar Mohammed , Sowjanya Komatineni , Mantravadi Karthik , Bitan Biswas Subject: [PATCH V5 6/7] i2c: tegra: fix PIO rx/tx residual transfer check Date: Tue, 11 Jun 2019 03:51:13 -0700 Message-ID: <1560250274-18499-6-git-send-email-bbiswas@nvidia.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560250274-18499-1-git-send-email-bbiswas@nvidia.com> References: <1560250274-18499-1-git-send-email-bbiswas@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1560250485; bh=DnwBZrSx2+8LhMKPSbReeXUfovA6frfU5DW0aOdqwo4=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=BwbdazJUfAo2KZXZmR+tmcjFjGYFLLBGv5gRRsZLS7ikcbcCN2cbKPD/ClwjauLNV w+EjmN3rf3G58L8jUEKgLDuwhg2f/+0LBoGQCTHsLVT13+jB/+Dhk8G+ae2bzuGmdt FCRPBz/JxZEfIZXqOUcoTC8Mi00nmbUYzZ2hcmY2VQm6dmaKNpx73YEcETsJLZcO/z ZNBSmHkx3CQ6IyOPwv23ptnWix+jKaKD2QWmofyBqa7xMtSjP7vBNWKVSVNRBIHzeT mr9mkNvGQeR+Ml57IV/Rq7YGwAve/HZnhN/45xelEBgpHHvjyaHDT2J3/neiNsVNZ1 dMhnfsv8ECOXA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix expression for residual bytes(less than word) transfer in I2C PIO mode RX/TX. Signed-off-by: Bitan Biswas --- drivers/i2c/busses/i2c-tegra.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 4dfb4c1..0596c12 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -514,7 +514,8 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) * If there is a partial word at the end of buf, handle it manually to * prevent overwriting past the end of buf */ - if (rx_fifo_avail > 0 && buf_remaining > 0) { + if (rx_fifo_avail > 0 && + (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) { BUG_ON(buf_remaining > 3); val = i2c_readl(i2c_dev, I2C_RX_FIFO); val = cpu_to_le32(val); @@ -557,11 +558,10 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) words_to_transfer = tx_fifo_avail; /* - * Update state before writing to FIFO. If this casues us + * Update state before writing to FIFO. If this causes us * to finish writing all bytes (AKA buf_remaining goes to 0) we * have a potential for an interrupt (PACKET_XFER_COMPLETE is - * not maskable). We need to make sure that the isr sees - * buf_remaining as 0 and doesn't call us back re-entrantly. + * not maskable). */ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD; tx_fifo_avail -= words_to_transfer; @@ -580,7 +580,8 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) * prevent reading past the end of buf, which could cross a page * boundary and fault. */ - if (tx_fifo_avail > 0 && buf_remaining > 0) { + if (tx_fifo_avail > 0 && + (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) { BUG_ON(buf_remaining > 3); memcpy(&val, buf, buf_remaining); val = le32_to_cpu(val); -- 2.7.4