From patchwork Sat Mar 2 13:47:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 10836605 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 367DE17E9 for ; Sat, 2 Mar 2019 13:48:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 167C32B2C9 for ; Sat, 2 Mar 2019 13:48:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0AD842B33B; Sat, 2 Mar 2019 13:48:17 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham 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 4D1862B2C9 for ; Sat, 2 Mar 2019 13:48:16 +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=WqLfIfhAPMeyc/nFpN7kZBAKn+Hgwm9sh5kFxtgXvoY=; b=I2klvyEn+3RH2V6O2/BSPeoMHc xHzL80IhianNFJLtKzXMC3yYS3BkAUI5tG+TsRhD0lXjf1eDLmrwUj+FhgwDeciV4jsu1cVd9l+4F xoHjfH6nfWPlbiETZVRDesLravKx8koPeV5+Y2l6Z9esQCMFgMbJxkoIl1gxOdpSlGzwpsS2mxI9U RR3xuu9SDFlC1thoptItCVh978gigQMEESO6NcUb1lV1pBn+7N8Ug//7GC86eN7Z6FHQenOSd+eiz 4M7NpPxBuCgwxHGrGubZQXjBB037aAR7gaPUmKIVkpYS8vxnhaKKsLdFvN4Xh1YPIEnDnOFhbD061 0N1Kcdew==; 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 1h04zr-0001bU-UB; Sat, 02 Mar 2019 13:48:11 +0000 Received: from sauhun.de ([88.99.104.3] helo=pokefinder.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h04zX-00013O-7W for linux-arm-kernel@lists.infradead.org; Sat, 02 Mar 2019 13:47:54 +0000 Received: from localhost (p54B33179.dip0.t-ipconnect.de [84.179.49.121]) by pokefinder.org (Postfix) with ESMTPSA id 5397B4A1774; Sat, 2 Mar 2019 14:47:44 +0100 (CET) From: Wolfram Sang To: linux-i2c@vger.kernel.org Subject: [RFC PATCH v2 2/7] i2c: core: use I2C locking behaviour also for SMBUS Date: Sat, 2 Mar 2019 14:47:30 +0100 Message-Id: <20190302134735.4393-3-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190302134735.4393-1-wsa+renesas@sang-engineering.com> References: <20190302134735.4393-1-wsa+renesas@sang-engineering.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190302_054751_416652_94BA140A X-CRM114-Status: GOOD ( 12.99 ) 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 , Phil Reid , Tony Lindgren , Keerthy , linux-kernel@vger.kernel.org, Russell King , linux-renesas-soc@vger.kernel.org, Wolfram Sang , linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org, Stefan Lengfeld , Andy Shevchenko , Peter Rosin , 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 Acked-by: Tony Lindgren Reviewed-by: Geert Uytterhoeven Reviewed-by: Simon Horman --- 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 cb6c5cb0df0b..004f8a3b6365 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1946,14 +1946,9 @@ 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 132119112596..357e083e8f45 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,