From patchwork Fri Oct 2 15:23:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Eggers X-Patchwork-Id: 11813829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AA9E7139A for ; Fri, 2 Oct 2020 15:27:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7D730206DC for ; Fri, 2 Oct 2020 15:27:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="RtrcjO3N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D730206DC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arri.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=MfL/S9Ms2mvn6iBPMIajoq6Ur7Ur7UCwj8wc8/jequA=; b=RtrcjO3N3nwK2QLjzQAxJ4nri yBBluRVPbTQWwiDRX5mcr8q/bDaqWc+WOSzKehzFDmE+ZUbRK2ze4i47G4dh8WuuZwemQyPQeUoOl YwDBm8dp83Y+zbVlTfdUco08inMJfy1nfbLh24F5WPI7ltpDuyxYNJZLfNrqcscOYjV3Z/KutQRKA oTHbofA3LPTVl1L0vAg4YhZiPir/0bYyT1vv1MvRHfNjwpiH5rdgTOwFpZY0Y5+QHD9aH4gYUjOcd nfSm+ipIUm5AOdgMtEQzjOiemA/MOG4ChhTa9pCxhL/Yff+AdPJKd+cl1SUbzi2PQlwuYYYFT5Q5o yjKwTm0kg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOMxg-00030e-08; Fri, 02 Oct 2020 15:27:08 +0000 Received: from mailout10.rmx.de ([94.199.88.75]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOMxc-0002xs-Lj for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2020 15:27:05 +0000 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 mailout10.rmx.de (Postfix) with ESMTPS id 4C2v425qLRz32Fq; Fri, 2 Oct 2020 17:26:58 +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 4C2v380YFgz2TRjr; Fri, 2 Oct 2020 17:26:12 +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 17:25:37 +0200 From: Christian Eggers To: Oleksij Rempel , Shawn Guo , Sascha Hauer , Fabio Estevam , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= Subject: [PATCH v2 3/3] i2c: imx: Don't generate STOP condition if arbitration has been lost Date: Fri, 2 Oct 2020 17:23:05 +0200 Message-ID: <20201002152305.4963-4-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: 20201002-172614-4C2v380YFgz2TRjr-0@kdin02 X-RMX-SOURCE: 217.111.95.66 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201002_112704_972687_E1B67946 X-CRM114-Status: GOOD ( 15.71 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [94.199.88.75 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [94.199.88.75 listed in wl.mailspike.net] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, NXP Linux Team , Pengutronix Kernel Team , Christian Eggers , linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org If arbitration is lost, the master automatically changes to slave mode. I2SR_IBB may or may not be reset by hardware. Raising a STOP condition by resetting I2CR_MSTA has no effect and will not clear I2SR_IBB. So calling i2c_imx_bus_busy() is not required and would busy-wait until timeout. Signed-off-by: Christian Eggers Cc: stable@vger.kernel.org # Requires trivial backporting, simple remove # the 3rd argument from the calls to # i2c_imx_bus_busy(). Tested-by: Krzysztof Kozlowski --- drivers/i2c/busses/i2c-imx.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 1db1e2f5296e..ced9cb3a2665 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -616,6 +616,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic) /* Stop I2C transaction */ dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); if (i2c_imx->dma) temp &= ~I2CR_DMAEN; @@ -785,9 +787,12 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, */ dev_dbg(dev, "<%s> clear MSTA\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - i2c_imx_bus_busy(i2c_imx, 0, false); + if (!i2c_imx->stopped) + i2c_imx_bus_busy(i2c_imx, 0, false); } else { /* * For i2c master receiver repeat restart operation like: @@ -912,9 +917,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, dev_dbg(&i2c_imx->adapter.dev, "<%s> clear MSTA\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - i2c_imx_bus_busy(i2c_imx, 0, atomic); + if (!i2c_imx->stopped) + i2c_imx_bus_busy(i2c_imx, 0, atomic); } else { /* * For i2c master receiver repeat restart operation like: