From patchwork Thu Sep 20 16:14:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 10608127 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1C672161F for ; Thu, 20 Sep 2018 16:27:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04A1A2E156 for ; Thu, 20 Sep 2018 16:27:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC46A2E15D; Thu, 20 Sep 2018 16:27:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8D6A02E156 for ; Thu, 20 Sep 2018 16:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=t8o5dYHqO5Fmh2D8RtLLBYlzbMN4kCCpxcVApNE2bvs=; b=ih60+tWNY63kF00R+X+d1rzQMI FA0sxrB84U0eAQ/fH7NA4pS8FhfAN++Yjt2cF66TgN6tVm2vTEC+3OPIX026fS2WZIwkAxDQV431X dRDCv2l/0i1b+LJyTWCrNo3k3Eq7av7NeIhUXAMTy85/2g9OmtfbswagIaiJu+41PoGz+s3Xevdtj oajvpO0aA4W7XMHwzdoZXuxpOyr9qykSBYl4CxrbkAJB3wvI7/mcad4JNptEg8nV38JipsbvtyjKw 8BiJ5wXkmqLibLbaXAtpc0hocx9CwIST4R7I1zTEMks6xv00zC/WQEB/i7XCN0JFdlCdmCRc5uLUq Z+JPFe+w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g31nb-0002LN-VT; Thu, 20 Sep 2018 16:27:27 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1g31mq-0001by-Ft for linux-arm-kernel@bombadil.infradead.org; Thu, 20 Sep 2018 16:26:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Jbp4xJ8CLlwD3ltkLcdDSLwnAaFTbrp++k+mHjvhCZk=; b=FeAX34t0vaIeEsISc5+8gRebk SUq5VDdzj7C148jZI6hsORCF+hGXvTzZQkwu6Cup1oyfTtxHXTD9FOfYm/OzLTJI9zmMF9GOcAJnn z0c3N3gaPdfIDhdNYP4VW9Qx4bH2Z8RXr6WXJimQEsFVXeQ3ihRLT7OBujk23pwLvGnka9T1LUZu7 D3+VifNB3WeCxQNV9Hd+8ff5Gog4FPZKH65P24KPg+lLqneULsdrbVMeY4O9K/oUOA9W5kj2ldDji MuP2KQteEHVoZYdJ3Wp+ji1TTytkSR0t6zTnhPrkWnVSRJVXac7kS05A/WVpHwG84EGPco63bY/kO cqUPSrCkg==; Received: from sauhun.de ([88.99.104.3] helo=pokefinder.org) by casper.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g31bJ-0003Ci-B1 for linux-arm-kernel@lists.infradead.org; Thu, 20 Sep 2018 16:14:47 +0000 Received: from localhost (i577B999D.versanet.de [87.123.153.157]) by pokefinder.org (Postfix) with ESMTPSA id 1CF462E35A4; Thu, 20 Sep 2018 18:14:34 +0200 (CEST) From: Wolfram Sang To: linux-i2c@vger.kernel.org Subject: [RFC PATCH 3/4] i2c: core: use I2C locking behaviour also for SMBUS Date: Thu, 20 Sep 2018 18:14:22 +0200 Message-Id: <20180920161423.13990-4-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180920161423.13990-1-wsa+renesas@sang-engineering.com> References: <20180920161423.13990-1-wsa+renesas@sang-engineering.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180920_171446_223271_888BCFBC X-CRM114-Status: GOOD ( 13.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tero Kristo , preid@electromag.com.au, Keerthy , Andy Shevchenko , linux-renesas-soc@vger.kernel.org, Wolfram Sang , Grygorii Strashko , Stefan Lengfeld , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP If I2C transfers are executed in atomic contexts, trylock is used instead of lock. This behaviour was missing for SMBUS, although a lot of transfers are of SMBUS type, either emulated or direct. So, factor out the locking routine into a helper and use it for I2C and SMBUS. Signed-off-by: Wolfram Sang Acked-by: Peter Rosin --- drivers/i2c/i2c-core-base.c | 11 +++-------- drivers/i2c/i2c-core-smbus.c | 7 ++++++- drivers/i2c/i2c-core.h | 12 ++++++++++++ 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 799776c6d421..904b4d2ebefa 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1943,14 +1943,9 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) * one (discarding status on the second message) or errno * (discarding status on the first one). */ - if (in_atomic() || irqs_disabled()) { - ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); - if (!ret) - /* I2C activity is ongoing. */ - return -EAGAIN; - } else { - i2c_lock_bus(adap, I2C_LOCK_SEGMENT); - } + ret = __i2c_lock_bus_helper(adap); + if (ret) + return ret; ret = __i2c_transfer(adap, msgs, num); i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 9cd66cabb84f..dbb46edb8e02 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -20,6 +20,8 @@ #include #include +#include "i2c-core.h" + #define CREATE_TRACE_POINTS #include @@ -530,7 +532,10 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, { s32 res; - i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); + res = __i2c_lock_bus_helper(adapter); + if (res) + return res; + res = __i2c_smbus_xfer(adapter, addr, flags, read_write, command, protocol, data); i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index 37576f50fe20..6e98aa811980 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -29,6 +29,18 @@ extern int __i2c_first_dynamic_bus_num; int i2c_check_7bit_addr_validity_strict(unsigned short addr); +static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) +{ + int ret = 0; + + if (in_atomic() || irqs_disabled()) + ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN; + else + i2c_lock_bus(adap, I2C_LOCK_SEGMENT); + + return ret; +} + #ifdef CONFIG_ACPI const struct acpi_device_id * i2c_acpi_match_device(const struct acpi_device_id *matches,