From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: [PATCH 02/12] i2c: core: use I2C locking behaviour also for SMBUS Date: Wed, 3 Apr 2019 14:40:09 +0200 Message-ID: <20190403124019.8947-3-wsa+renesas@sang-engineering.com> References: <20190403124019.8947-1-wsa+renesas@sang-engineering.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190403124019.8947-1-wsa+renesas@sang-engineering.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: linux-i2c@vger.kernel.org Cc: Andy Shevchenko , Linus Walleij , linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Wolfram Sang , linux-tegra@vger.kernel.org, Stefan Lengfeld , linux-omap@vger.kernel.org, Peter Rosin , linux-arm-kernel@lists.infradead.org List-Id: linux-i2c@vger.kernel.org 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 f8502064cd6b..ad14f38a67e4 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 (i2c_in_atomic_xfer_mode()) { - 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 9d8526415b26..deea47c576e5 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -39,6 +39,18 @@ static inline bool i2c_in_atomic_xfer_mode(void) return system_state > SYSTEM_RUNNING && irqs_disabled(); } +static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) +{ + int ret = 0; + + if (i2c_in_atomic_xfer_mode()) + 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, -- 2.11.0