From patchwork Fri Oct 2 15:23:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Eggers X-Patchwork-Id: 285735 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=-12.7 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 0C9C2C4363C for ; Fri, 2 Oct 2020 15:26:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4BE820719 for ; Fri, 2 Oct 2020 15:26:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388317AbgJBP0Q (ORCPT ); Fri, 2 Oct 2020 11:26:16 -0400 Received: from mailout04.rmx.de ([94.199.90.94]:34254 "EHLO mailout04.rmx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBP0Q (ORCPT ); Fri, 2 Oct 2020 11:26:16 -0400 Received: from kdin02.retarus.com (kdin02.dmz1.retloc [172.19.17.49]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout04.rmx.de (Postfix) with ESMTPS id 4C2v380fkFz3qxK9; Fri, 2 Oct 2020 17:26:12 +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 kdin02.retarus.com (Postfix) with ESMTPS id 4C2v2K2Psbz2TSGr; Fri, 2 Oct 2020 17:25:29 +0200 (CEST) Received: from N95HX1G2.wgnetz.xx (192.168.54.33) by mta.arri.de (192.168.100.104) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 2 Oct 2020 17:25:02 +0200 From: Christian Eggers To: Oleksij Rempel , Shawn Guo , Sascha Hauer , Fabio Estevam , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= CC: Pengutronix Kernel Team , NXP Linux Team , , , , Christian Eggers , Subject: [PATCH v2 2/3] i2c: imx: Check for I2SR_IAL after every byte Date: Fri, 2 Oct 2020 17:23:04 +0200 Message-ID: <20201002152305.4963-3-ceggers@arri.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201002152305.4963-1-ceggers@arri.de> References: <20201002152305.4963-1-ceggers@arri.de> MIME-Version: 1.0 X-Originating-IP: [192.168.54.33] X-RMX-ID: 20201002-172529-4C2v2K2Psbz2TSGr-0@kdin02 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 Tested-by: Krzysztof Kozlowski --- drivers/i2c/busses/i2c-imx.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 34648df7f1a6..1db1e2f5296e 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -483,6 +483,24 @@ 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; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); + /* + * i2sr_clr_opcode is the value to clear all interrupts. + * Here we want to clear only I2SR_IAL, so we write + * ~i2sr_clr_opcode with just the I2SR_IAL bit toggled. + */ + 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;