From patchwork Thu Mar 9 14:05:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javier Martinez Canillas X-Patchwork-Id: 9613417 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1A374604D9 for ; Thu, 9 Mar 2017 14:06:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07C172846C for ; Thu, 9 Mar 2017 14:06:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F04572863F; Thu, 9 Mar 2017 14:06:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A05712846C for ; Thu, 9 Mar 2017 14:06:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932193AbdCIOF5 (ORCPT ); Thu, 9 Mar 2017 09:05:57 -0500 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:49192 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754814AbdCIOF4 (ORCPT ); Thu, 9 Mar 2017 09:05:56 -0500 Received: from localhost (localhost [127.0.0.1]) by osg.samsung.com (Postfix) with ESMTP id CBCCFA12FC; Thu, 9 Mar 2017 14:06:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osg.samsung.com Received: from osg.samsung.com ([127.0.0.1]) by localhost (s-opensource.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YRW4Oig8A0Vn; Thu, 9 Mar 2017 14:06:06 +0000 (UTC) Received: from localhost.localdomain (unknown [181.121.136.80]) by osg.samsung.com (Postfix) with ESMTPSA id 8F344A0C15; Thu, 9 Mar 2017 14:06:02 +0000 (UTC) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: Inki Dae , Andi Shyti , Mauro Carvalho Chehab , Shuah Khan , Javier Martinez Canillas , Kukjin Kim , Wolfram Sang , linux-samsung-soc@vger.kernel.org, Krzysztof Kozlowski , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] i2c: exynos5: Avoid transaction timeouts due TRANSFER_DONE_AUTO not set Date: Thu, 9 Mar 2017 11:05:33 -0300 Message-Id: <20170309140533.24618-1-javier@osg.samsung.com> X-Mailer: git-send-email 2.9.3 Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP After commit 7999eecb7e56 ("i2c: exynos5: fix arbitration lost handling"), some I2C transactions are failing because the TRANSFER_DONE_AUTO field is not set in the I2C_TRANS_STATUS register so the i2c->status value is left to -EINVAL causing the i2c->msg_complete completion to never be signaled. For example, when reading the time of an I2C rtc on an Exynos5800 machine: $ cat /sys/class/rtc/rtc0/time [ 25.924594] exynos5-hsi2c 12e10000.i2c: rx timeout [ 65.028365] max77686-rtc max77802-rtc: Fail to read time reg(-22) cat: /sys/class/rtc/rtc0/time: Invalid argument The Exynos5422 manual states clearly that most I2C_TRANS_STATUS reg bits (including TRANSFER_DONE_AUTO) are cleared after the register is read. So reading has side effects and should only be done if HSI2C_INT_I2C was set. Fixes: 7999eecb7e56 ("i2c: exynos5: fix arbitration lost handling") Signed-off-by: Javier Martinez Canillas Reviewed-by: Andrzej Hajda --- drivers/i2c/busses/i2c-exynos5.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c index cbd93ce0661f..736a82472101 100644 --- a/drivers/i2c/busses/i2c-exynos5.c +++ b/drivers/i2c/busses/i2c-exynos5.c @@ -457,7 +457,6 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) int_status = readl(i2c->regs + HSI2C_INT_STATUS); writel(int_status, i2c->regs + HSI2C_INT_STATUS); - trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); /* handle interrupt related to the transfer status */ if (i2c->variant->hw == HSI2C_EXYNOS7) { @@ -482,11 +481,13 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) goto stop; } + trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); if ((trans_status & HSI2C_MASTER_ST_MASK) == HSI2C_MASTER_ST_LOSE) { i2c->state = -EAGAIN; goto stop; } } else if (int_status & HSI2C_INT_I2C) { + trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); if (trans_status & HSI2C_NO_DEV_ACK) { dev_dbg(i2c->dev, "No ACK from device\n"); i2c->state = -ENXIO;