From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sauhun.de ([88.99.104.3]:60958 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727659AbeITV6s (ORCPT ); Thu, 20 Sep 2018 17:58:48 -0400 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Stefan Lengfeld , preid@electromag.com.au, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Keerthy , Tero Kristo , Grygorii Strashko , Andy Shevchenko , Wolfram Sang 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> In-Reply-To: <20180920161423.13990-1-wsa+renesas@sang-engineering.com> References: <20180920161423.13990-1-wsa+renesas@sang-engineering.com> Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: 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 --- 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, -- 2.18.0