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From: Wolfram Sang <wsa@the-dreams.de>
To: Daniel Baluta <daniel.baluta@intel.com>
Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
	pmeerw@pmeerw.net, linux-iio@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
	lucas.demarchi@intel.com, srinivas.pandruvada@linux.intel.com,
	ggao@invensense.com, adi.reus@gmail.com, cmo@melexis.com,
	mwelling@ieee.org
Subject: Re: [RFC PATCH 0/9] iio: Fix ABBA deadlock in inv-mpu6050
Date: Mon, 22 Feb 2016 00:17:51 +0100	[thread overview]
Message-ID: <20160221231751.GC1386@katana> (raw)
In-Reply-To: <1455810794-3188-1-git-send-email-daniel.baluta@intel.com>

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On Thu, Feb 18, 2016 at 05:53:05PM +0200, Daniel Baluta wrote:
> 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.

We recently had a bigger patch series fixing locking problems related to
muxes. I sadly didn't have the time to review it. Can you have a look if
it helps your case?

http://thread.gmane.org/gmane.linux.drivers.i2c/26169

Thanks,

   Wolfram


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  parent reply	other threads:[~2016-02-21 23:18 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-18 15:53 [RFC PATCH 0/9] iio: Fix ABBA deadlock in inv-mpu6050 Daniel Baluta
2016-02-18 15:53 ` [RFC PATCH 1/9] iio: imu: inv_mpu6050: Fix multiline comments style Daniel Baluta
2016-02-21 20:36   ` Jonathan Cameron
2016-02-18 15:53 ` [RFC PATCH 2/9] iio: imu: inv_mpu6050: Fix Yoda conditions Daniel Baluta
2016-02-19  9:09   ` Crt Mori
2016-02-21 20:38     ` Jonathan Cameron
2016-03-01 21:23   ` Wolfram Sang
2016-02-18 15:53 ` [RFC PATCH 3/9] iio: imu: inv_mpu6050: Fix newlines to make code easier to read Daniel Baluta
2016-02-21 20:38   ` Jonathan Cameron
2016-02-18 15:53 ` [RFC PATCH 4/9] iio: imu: inv_mpu6050: Remove unnecessary parentheses Daniel Baluta
2016-02-21 20:39   ` Jonathan Cameron
2016-02-18 15:53 ` [RFC PATCH 5/9] iio: imu: inv_mpu6050: Delete space before comma Daniel Baluta
2016-02-18 15:53 ` [RFC PATCH 6/9] iio: imu: inv_mpu6050: Fix code indent for if statement Daniel Baluta
2016-02-21 20:40   ` Jonathan Cameron
2016-02-18 15:53 ` [RFC PATCH 7/9] iio: imu: inv_mpu6050: Fix alignment with open parenthesis Daniel Baluta
2016-02-21 20:41   ` Jonathan Cameron
2016-02-21 20:59     ` Joe Perches
2016-02-21 21:08       ` Jonathan Cameron
2016-02-18 15:53 ` [RFC PATCH 8/9] i2c: i2c-mux: Allow for NULL select callback Daniel Baluta
2016-03-01 20:30   ` Wolfram Sang
2016-03-01 20:38     ` Daniel Baluta
2016-02-18 15:53 ` [RFC PATCH 9/9] iio: imu: inv_mpu6050: Fix deadlock between i2c adapter lock and mpu lock Daniel Baluta
2016-02-18 18:17   ` Srinivas Pandruvada
2016-02-19 20:17     ` Ge Gao
2016-03-01 20:50   ` Wolfram Sang
2016-03-02 16:33     ` Daniel Baluta
2016-03-02 17:06       ` Wolfram Sang
2016-02-21 23:17 ` Wolfram Sang [this message]
2016-02-22  9:43   ` [RFC PATCH 0/9] iio: Fix ABBA deadlock in inv-mpu6050 Daniel Baluta
2016-02-26 15:52   ` Daniel Baluta
2016-03-03 23:09     ` Peter Rosin
2016-03-04 10:20       ` Daniel Baluta

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