From patchwork Mon Oct 23 08:11:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Huangzheng Lai X-Patchwork-Id: 737410 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 54D94C25B42 for ; Mon, 23 Oct 2023 08:13:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232208AbjJWINR (ORCPT ); Mon, 23 Oct 2023 04:13:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229926AbjJWINB (ORCPT ); Mon, 23 Oct 2023 04:13:01 -0400 Received: from SHSQR01.spreadtrum.com (mx1.unisoc.com [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65503D65; Mon, 23 Oct 2023 01:12:57 -0700 (PDT) Received: from dlp.unisoc.com ([10.29.3.86]) by SHSQR01.spreadtrum.com with ESMTP id 39N8CVvw060127; Mon, 23 Oct 2023 16:12:31 +0800 (+08) (envelope-from Huangzheng.Lai@unisoc.com) Received: from SHDLP.spreadtrum.com (shmbx04.spreadtrum.com [10.0.1.214]) by dlp.unisoc.com (SkyGuard) with ESMTPS id 4SDSVc2FJWz2LHnPx; Mon, 23 Oct 2023 16:08:08 +0800 (CST) Received: from xm9614pcu.spreadtrum.com (10.13.2.29) by shmbx04.spreadtrum.com (10.0.1.214) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Mon, 23 Oct 2023 16:12:28 +0800 From: Huangzheng Lai To: Andi Shyti CC: Orson Zhai , Baolin Wang , Chunyan Zhang , , , huangzheng lai , Huangzheng Lai , Xiongpeng Wu Subject: [PATCH V2 3/7] i2c: sprd: Use global variables to record I2C ack/nack status instead of local variables Date: Mon, 23 Oct 2023 16:11:54 +0800 Message-ID: <20231023081158.10654-4-Huangzheng.Lai@unisoc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20231023081158.10654-1-Huangzheng.Lai@unisoc.com> References: <20231023081158.10654-1-Huangzheng.Lai@unisoc.com> MIME-Version: 1.0 X-Originating-IP: [10.13.2.29] X-ClientProxiedBy: SHCAS01.spreadtrum.com (10.0.1.201) To shmbx04.spreadtrum.com (10.0.1.214) X-MAIL: SHSQR01.spreadtrum.com 39N8CVvw060127 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org We found that when the interrupt bit of the I2C controller is cleared, the ack/nack bit is also cleared at the same time. After clearing the interrupt bit in sprd_i2c_isr(), incorrect ack/nack information will be obtained in sprd_i2c_isr_thread(), resulting in incorrect communication when nack cannot be recognized. To solve this problem, we used a global variable to record ack/nack information before clearing the interrupt bit instead of a local variable. Fixes: 8b9ec0719834 ("i2c: Add Spreadtrum I2C controller driver") Cc: # v4.14+ Signed-off-by: Huangzheng Lai --- drivers/i2c/busses/i2c-sprd.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c index aa602958d4fd..dec627ef408c 100644 --- a/drivers/i2c/busses/i2c-sprd.c +++ b/drivers/i2c/busses/i2c-sprd.c @@ -85,6 +85,7 @@ struct sprd_i2c { struct clk *clk; u32 src_clk; u32 bus_freq; + bool ack_flag; struct completion complete; struct reset_control *rst; u8 *buf; @@ -119,6 +120,7 @@ static void sprd_i2c_clear_ack(struct sprd_i2c *i2c_dev) { u32 tmp = readl(i2c_dev->base + I2C_STATUS); + i2c_dev->ack_flag = 0; writel(tmp & ~I2C_RX_ACK, i2c_dev->base + I2C_STATUS); } @@ -393,7 +395,6 @@ static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id) { struct sprd_i2c *i2c_dev = dev_id; struct i2c_msg *msg = i2c_dev->msg; - bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK); u32 i2c_tran; if (msg->flags & I2C_M_RD) @@ -409,7 +410,7 @@ static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id) * For reading data, ack is always true, if i2c_tran is not 0 which * means we still need to contine to read data from slave. */ - if (i2c_tran && ack) { + if (i2c_tran && i2c_dev->ack_flag) { sprd_i2c_data_transfer(i2c_dev); return IRQ_HANDLED; } @@ -420,7 +421,7 @@ static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id) * If we did not get one ACK from slave when writing data, we should * return -EIO to notify users. */ - if (!ack) + if (!i2c_dev->ack_flag) i2c_dev->err = -EIO; else if (msg->flags & I2C_M_RD && i2c_dev->count) sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, i2c_dev->count); @@ -437,7 +438,6 @@ static irqreturn_t sprd_i2c_isr(int irq, void *dev_id) { struct sprd_i2c *i2c_dev = dev_id; struct i2c_msg *msg = i2c_dev->msg; - bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK); u32 i2c_tran; if (msg->flags & I2C_M_RD) @@ -456,7 +456,8 @@ static irqreturn_t sprd_i2c_isr(int irq, void *dev_id) * means we can read all data in one time, then we can finish this * transmission too. */ - if (!i2c_tran || !ack) { + i2c_dev->ack_flag = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK); + if (!i2c_tran || !i2c_dev->ack_flag) { sprd_i2c_clear_start(i2c_dev); sprd_i2c_clear_irq(i2c_dev); }