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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3C327C2BCA1 for ; Fri, 7 Jun 2019 12:08:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 116D9212F5 for ; Fri, 7 Jun 2019 12:08:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Job7TbfO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728398AbfFGMI3 (ORCPT ); Fri, 7 Jun 2019 08:08:29 -0400 Received: from mail-io1-f66.google.com ([209.85.166.66]:34167 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727386AbfFGMI3 (ORCPT ); Fri, 7 Jun 2019 08:08:29 -0400 Received: by mail-io1-f66.google.com with SMTP id k8so1216558iot.1; Fri, 07 Jun 2019 05:08:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=9Jt/byb9nrWN493RX0emzJG/99YlfQT5TXBjwjLl2N4=; b=Job7TbfOu9s088soz/nsa2sgbToNs00hR89VRmIuZRIqNtJQQEh+Q3S6X88Ry4ijPT 28Yal5waNO2LxU86T3tUeQ5JFydaMLnrtgrPg23JGfHWvYJXi4XrWq0H3BBtLYFeWPI2 +h7T5JTq8XyaGuBwYIq+bt7gXq3oTjk/Cx0emnHpl50UPJC4Q3Da4qZLLS+i/52UtQOU BrrRfuVW3eh4/mR3uLEpqZ8H8A8uSPJnsY8btmoWko1Tz3uB7ElTLSIL7T2/Qn0/ctJ1 F3Ld5/DXM1H+MkdOfFcdvolEvrHlHTlcT4o1PuMkIEo+9ffaucCMc8iTGAye3snpPVLv xXvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=9Jt/byb9nrWN493RX0emzJG/99YlfQT5TXBjwjLl2N4=; b=adKhDAVZbWojln5Ki9sdHOwpPrhvXbqwF5BgjKvWlw7FYGy+DRwVhFtAye7Yfdp8qS W8lXptORhNd4VZJdf0I+Ky/mSivwo5bXrvWRkq+Y/ed/fxfpBwqWI6XqjwSSgSn5EgRn VcmAtnUH77VShuskab1d8xxpnoi+QGDL76C86EXUuEyNvJ+amWGHT5YML6GF9sbKGGfe k80JvwIkUfXbxlMyhxtZx1GsvNE66M0S6AQzeytqQRMubBUStEmAqnXbFGt4K2CgFaTZ 30KGX2LyoqchIoTtbiT9bEodqsaG++dftjFKRZ/qqT81w0DbWuPyQqfeiz36gFITBlhP yXrA== X-Gm-Message-State: APjAAAU7VkAlzQ7Wn4QYWpwTvurKTYKVnyZlz4J4eoTQTXp7H6WA9Rys hpxqaujVkX0S9yUdW0eN5gk= X-Google-Smtp-Source: APXvYqw3bKY9W1oEVOwpnvqB4F4RM1/VoD6twJgvgAgqMSlp9qSxqx383gdyYlN192OnYZZHzExHsg== X-Received: by 2002:a5d:9550:: with SMTP id a16mr2468747ios.106.1559909308461; Fri, 07 Jun 2019 05:08:28 -0700 (PDT) Received: from [192.168.2.145] (ppp91-76-170-54.pppoe.mtu-net.ru. [91.76.170.54]) by smtp.googlemail.com with ESMTPSA id c91sm4692772itd.4.2019.06.07.05.08.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Jun 2019 05:08:28 -0700 (PDT) Subject: Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON To: Bitan Biswas , 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 Cc: Shardar Mohammed , Sowjanya Komatineni , Mantravadi Karthik References: <1559908507-31192-1-git-send-email-bbiswas@nvidia.com> <1559908507-31192-6-git-send-email-bbiswas@nvidia.com> From: Dmitry Osipenko Message-ID: <4aec6d7a-0dea-18c9-efde-96cc1a54b945@gmail.com> Date: Fri, 7 Jun 2019 15:08:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1559908507-31192-6-git-send-email-bbiswas@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 07.06.2019 14:55, Bitan Biswas пишет: > Remove redundant BUG_ON calls or replace with WARN_ON_ONCE > as needed. Replace BUG() with error handling code. > Define I2C_ERR_UNEXPECTED_STATUS for error handling. > > Signed-off-by: Bitan Biswas > --- > drivers/i2c/busses/i2c-tegra.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c > index 4dfb4c1..c407bd7 100644 > --- a/drivers/i2c/busses/i2c-tegra.c > +++ b/drivers/i2c/busses/i2c-tegra.c > @@ -73,6 +73,7 @@ > #define I2C_ERR_NO_ACK BIT(0) > #define I2C_ERR_ARBITRATION_LOST BIT(1) > #define I2C_ERR_UNKNOWN_INTERRUPT BIT(2) > +#define I2C_ERR_UNEXPECTED_STATUS BIT(3) > > #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28 > #define PACKET_HEADER0_PACKET_ID_SHIFT 16 > @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) > * prevent overwriting past the end of buf > */ > if (rx_fifo_avail > 0 && buf_remaining > 0) { > - BUG_ON(buf_remaining > 3); > val = i2c_readl(i2c_dev, I2C_RX_FIFO); > val = cpu_to_le32(val); > memcpy(buf, &val, buf_remaining); > @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) > rx_fifo_avail--; > } > > - BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0); > i2c_dev->msg_buf_remaining = buf_remaining; > i2c_dev->msg_buf = buf; > > @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) > * boundary and fault. > */ > if (tx_fifo_avail > 0 && buf_remaining > 0) { > - BUG_ON(buf_remaining > 3); > memcpy(&val, buf, buf_remaining); > val = le32_to_cpu(val); > > @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) > > if (!i2c_dev->is_curr_dma_xfer) { > if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) { > - if (i2c_dev->msg_buf_remaining) > + if (i2c_dev->msg_buf_remaining) { > tegra_i2c_empty_rx_fifo(i2c_dev); > - else > - BUG(); > + } else { > + dev_err(i2c_dev->dev, "unexpected rx data request\n"); > + i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS; > + goto err; > + } > } > > if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) { > @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) > if (status & I2C_INT_PACKET_XFER_COMPLETE) { > if (i2c_dev->is_curr_dma_xfer) > i2c_dev->msg_buf_remaining = 0; > - BUG_ON(i2c_dev->msg_buf_remaining); > + WARN_ON_ONCE(i2c_dev->msg_buf_remaining); > complete(&i2c_dev->msg_complete); > } > goto done; > Very nice, thank you very much! BTW, I think it may worth to add another patch that will reset hardware state in a case of the warning since we know that something gone wrong. Reviewed-by: Dmitry Osipenko