From patchwork Tue Oct 6 16:08:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Eggers X-Patchwork-Id: 1377534 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=arri.de Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4C5Ms56htmz9sTK for ; Wed, 7 Oct 2020 03:11:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726137AbgJFQLB (ORCPT ); Tue, 6 Oct 2020 12:11:01 -0400 Received: from mailout11.rmx.de ([94.199.88.76]:50652 "EHLO mailout11.rmx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725769AbgJFQLB (ORCPT ); Tue, 6 Oct 2020 12:11:01 -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 mailout11.rmx.de (Postfix) with ESMTPS id 4C5Mrw5w11z40qX; Tue, 6 Oct 2020 18:10:56 +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 4C5Mqn6vl6z2xZn; Tue, 6 Oct 2020 18:09:57 +0200 (CEST) Received: from N95HX1G2.wgnetz.xx (192.168.54.45) by mta.arri.de (192.168.100.104) with Microsoft SMTP Server (TLS) id 14.3.408.0; Tue, 6 Oct 2020 18:09:33 +0200 From: Christian Eggers To: Oleksij Rempel , Shawn Guo , Sascha Hauer , Fabio Estevam , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , "David Laight" CC: Pengutronix Kernel Team , NXP Linux Team , , , , Christian Eggers , Subject: [PATCH v4 2/3] i2c: imx: Check for I2SR_IAL after every byte Date: Tue, 6 Oct 2020 18:08:13 +0200 Message-ID: <20201006160814.22047-3-ceggers@arri.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201006160814.22047-1-ceggers@arri.de> References: <20201006160814.22047-1-ceggers@arri.de> MIME-Version: 1.0 X-Originating-IP: [192.168.54.45] X-RMX-ID: 20201006-181001-4C5Mqn6vl6z2xZn-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 | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index cbdcab73a055..63575af41c09 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -490,6 +490,16 @@ 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) { + dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); + i2c_imx_clear_irq(i2c_imx, I2SR_IAL); + + i2c_imx->i2csr = 0; + return -EAGAIN; + } + dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__); i2c_imx->i2csr = 0; return 0;