From patchwork Thu Sep 17 12:20:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Eggers X-Patchwork-Id: 254714 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,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 33CFDC43461 for ; Thu, 17 Sep 2020 12:58:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC8162075B for ; Thu, 17 Sep 2020 12:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727077AbgIQM6P (ORCPT ); Thu, 17 Sep 2020 08:58:15 -0400 Received: from mailout12.rmx.de ([94.199.88.78]:59194 "EHLO mailout12.rmx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726823AbgIQM6J (ORCPT ); Thu, 17 Sep 2020 08:58:09 -0400 Received: from kdin01.retarus.com (kdin01.dmz1.retloc [172.19.17.48]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout12.rmx.de (Postfix) with ESMTPS id 4BsbhM6kVbzRnbH; Thu, 17 Sep 2020 14:22:43 +0200 (CEST) Received: from mta.arri.de (unknown [217.111.95.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by kdin01.retarus.com (Postfix) with ESMTPS id 4BsbgT1D7qz2xKS; Thu, 17 Sep 2020 14:21:57 +0200 (CEST) Received: from N95HX1G2.wgnetz.xx (192.168.54.80) by mta.arri.de (192.168.100.104) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 17 Sep 2020 14:21:47 +0200 From: Christian Eggers To: Oleksij Rempel , Shawn Guo , Sascha Hauer , Fabio Estevam CC: Pengutronix Kernel Team , NXP Linux Team , , , , Christian Eggers , Subject: [PATCH 2/3] i2c: imx: Check for I2SR_IAL after every byte Date: Thu, 17 Sep 2020 14:20:28 +0200 Message-ID: <20200917122029.11121-3-ceggers@arri.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200917122029.11121-1-ceggers@arri.de> References: <20200917122029.11121-1-ceggers@arri.de> MIME-Version: 1.0 X-Originating-IP: [192.168.54.80] X-RMX-ID: 20200917-142203-4BsbgT1D7qz2xKS-0@kdin01 X-RMX-SOURCE: 217.111.95.66 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Arbitration Lost (IAL) can happen after every single byte transfer. If arbitration is lost, the I2C hardware will autonomously switch from master mode to slave. If a transfer is not aborted in this state, consecutive transfers will not be executed by the hardware and will timeout. Signed-off-by: Christian Eggers Cc: stable@vger.kernel.org --- drivers/i2c/busses/i2c-imx.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d8b2e632dd10..9d9b668ec7f2 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -479,6 +479,20 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic) dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); return -ETIMEDOUT; } + + /* check for arbitration lost */ + if (i2c_imx->i2csr & I2SR_IAL) { + unsigned int temp = i2c_imx->i2csr; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); + temp &= ~I2SR_IAL; + temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL); + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); + + i2c_imx->i2csr = 0; + return -EAGAIN; + } + dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__); i2c_imx->i2csr = 0; return 0;