From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 55A7CC4361B for ; Wed, 9 Dec 2020 10:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E9D123609 for ; Wed, 9 Dec 2020 10:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729149AbgLIKJF (ORCPT ); Wed, 9 Dec 2020 05:09:05 -0500 Received: from mailout03.rmx.de ([94.199.88.101]:47382 "EHLO mailout03.rmx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728631AbgLIKJF (ORCPT ); Wed, 9 Dec 2020 05:09:05 -0500 X-Greylist: delayed 2000 seconds by postgrey-1.27 at vger.kernel.org; Wed, 09 Dec 2020 05:09:04 EST 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 mailout03.rmx.de (Postfix) with ESMTPS id 4CrX2Y3fGvzlbGf; Wed, 9 Dec 2020 10:35:01 +0100 (CET) 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 4CrX2P3z5lz2ytY; Wed, 9 Dec 2020 10:34:53 +0100 (CET) Received: from N95HX1G2.wgnetz.xx (192.168.54.26) by mta.arri.de (192.168.100.104) with Microsoft SMTP Server (TLS) id 14.3.487.0; Wed, 9 Dec 2020 10:34:52 +0100 From: Christian Eggers To: CC: , , , Sudip Mukherjee , , , Christian Eggers Subject: [PATCH v5.4] i2c: imx: Check for I2SR_IAL after every byte Date: Wed, 9 Dec 2020 10:34:31 +0100 Message-ID: <20201209093431.15561-1-ceggers@arri.de> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [192.168.54.26] X-RMX-ID: 20201209-103453-KDVLhWwpmKss-0@out01.hq X-RMX-SOURCE: 217.111.95.66 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 1de67a3dee7a279ebe4d892b359fe3696938ec15 upstream. 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 Tested (not extensively) on Vybrid VF500 (Toradex VF50): Tested-by: Krzysztof Kozlowski Acked-by: Oleksij Rempel Cc: stable@vger.kernel.org --- Hi Greg, here is the patch for linux-5.4. Please let me know if this doesn't apply to older kernels. regards Christian On Wednesday, 9 December 2020, 09:33:00 CET, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 5.4-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From 1de67a3dee7a279ebe4d892b359fe3696938ec15 Mon Sep 17 00:00:00 2001 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 bba612cf775d..9d3f42fd6352 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -470,6 +470,16 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx) 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; -- Christian Eggers Embedded software developer Arnold & Richter Cine Technik GmbH & Co. Betriebs KG Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRA 57918 Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRB 54477 Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; Markus Zeiler