From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Baluta Subject: [RFC PATCH 0/9] iio: Fix ABBA deadlock in inv-mpu6050 Date: Thu, 18 Feb 2016 17:53:05 +0200 Message-ID: <1455810794-3188-1-git-send-email-daniel.baluta@intel.com> Return-path: Received: from mga02.intel.com ([134.134.136.20]:32180 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1425202AbcBRPu7 (ORCPT ); Thu, 18 Feb 2016 10:50:59 -0500 Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: jic23@kernel.org Cc: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, wsa@the-dreams.de, linux-i2c@vger.kernel.org, lucas.demarchi@intel.com, daniel.baluta@intel.com, srinivas.pandruvada@linux.intel.com, ggao@invensense.com, adi.reus@gmail.com, cmo@melexis.com, mwelling@ieee.org Sending this as an RFC because I don't know if style fixes are appropriate for this driver and also not sure if deadlock fix is the best solution. I2C people should only look at patches 8/9 and 9/9. The mpu6050 accel+gyro combo has an auxiliary I2C bus, allowing for an auxiliary sensor to be connected (eg. a magnetometer). The mpu can either act as an I2C master (functionality not currently implemented in the driver) or it can use a bypass multiplexer which directly connects the auxiliary I2C bus pins to the main I2C bus pins [1] Currently the driver implements the bypass mode via an I2C mux. This patchset fixes a deadlock in inv-mpu6050 IMU which happens when magnetometer (on auxiliary I2C bus) runs in parallel with accel or gyro. First 7 patches do some cleanup in order to make INV MPU6050 code easier to read. Patch number 8 allows passing NULL select callbacks to i2c_mux_master_xfer and i2c_mux_smbus_xfer. Patch number 9 actually fixes the deadlock. [1] (page 28, https://www.cdiweb.com/datasheets/invensense/MPU-6050_DataSheet_V3%204.pdf) Adriana Reus (2): i2c: i2c-mux: Allow for NULL select callback iio: imu: inv_mpu6050: Fix deadlock between i2c adapter lock and mpu lock Daniel Baluta (7): iio: imu: inv_mpu6050: Fix multiline comments style iio: imu: inv_mpu6050: Fix Yoda conditions iio: imu: inv_mpu6050: Fix newlines to make code easier to read iio: imu: inv_mpu6050: Remove unnecessary parentheses iio: imu: inv_mpu6050: Delete space before comma iio: imu: inv_mpu6050: Fix code indent for if statement iio: imu: inv_mpu6050: Fix alignment with open parenthesis drivers/i2c/i2c-mux.c | 10 ++- drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c | 6 +- drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 101 ++++++++++++++------------ drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c | 90 ++++------------------- drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 23 +++--- drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c | 22 +++--- 6 files changed, 102 insertions(+), 150 deletions(-) -- 2.5.0