Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934616AbdCVQSv (ORCPT ); Wed, 22 Mar 2017 12:18:51 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:33590 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934258AbdCVQS1 (ORCPT ); Wed, 22 Mar 2017 12:18:27 -0400 Date: Wed, 22 Mar 2017 21:50:43 +0530 From: simran singhal To: lars@metafoo.de Cc: Michael.Hennerich@analog.com, jic23@kernel.org, Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, outreachy-kernel@googlegroups.com Subject: [PATCH v8] staging: adis16060: Remove iio_dev mlock and refactor code Message-ID: <20170322162042.GA7955@singhal-Inspiron-5558> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3218 Lines: 112 The IIO subsystem is redefining iio_dev->mlock to be used by the IIO core only for protecting device operating mode changes. ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes. In this driver, mlock was being used to protect hardware state changes. In the driver, buf_lock protects both the adis16060_spi_write() and adis16060_spi_read() functions and both are always called in pair. First write, then read. Refactor the code to have one single function adis16060_spi_write_than_read() and remove the use of mlock as adis16060_read_raw() does not require an iio_dev->mlock for reads. Signed-off-by: simran singhal --- v8: -change subject -change commit message v7: -Change subject -Remove lock from read_raw instead from function adis16060_spi_write_than_read(). v6: -Change commit message -Remove nested lock v5: -Rename val in adis16060_spi_write_than_read() to conf. -Rename val2 in adis16060_spi_write_than_read() to val. -Corrected Checkpatch issues. -Removed goto from adis16060_read_raw(). v4: -Refactored code -change commit subject -change commit message v3: -Removed new lock to reuse the existing lock v2: -Fixed compilation error drivers/staging/iio/gyro/adis16060_core.c | 33 ++++++++----------------------- 1 file changed, 8 insertions(+), 25 deletions(-) diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c index c9d46e7..e96fce5 100644 --- a/drivers/staging/iio/gyro/adis16060_core.c +++ b/drivers/staging/iio/gyro/adis16060_core.c @@ -40,25 +40,18 @@ struct adis16060_state { static struct iio_dev *adis16060_iio_dev; -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val) +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev, + u8 conf, u16 *val) { int ret; struct adis16060_state *st = iio_priv(indio_dev); mutex_lock(&st->buf_lock); - st->buf[2] = val; /* The last 8 bits clocked in are latched */ + st->buf[2] = conf; /* The last 8 bits clocked in are latched */ ret = spi_write(st->us_w, st->buf, 3); - mutex_unlock(&st->buf_lock); - - return ret; -} - -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val) -{ - int ret; - struct adis16060_state *st = iio_priv(indio_dev); - mutex_lock(&st->buf_lock); + if (ret < 0) + return ret; ret = spi_read(st->us_r, st->buf, 3); @@ -86,17 +79,11 @@ static int adis16060_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: - /* Take the iio_dev status lock */ - mutex_lock(&indio_dev->mlock); - ret = adis16060_spi_write(indio_dev, chan->address); + ret = adis16060_spi_write_than_read(indio_dev, + chan->address, &tval); if (ret < 0) - goto out_unlock; + return ret; - ret = adis16060_spi_read(indio_dev, &tval); - if (ret < 0) - goto out_unlock; - - mutex_unlock(&indio_dev->mlock); *val = tval; return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: @@ -110,10 +97,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev, } return -EINVAL; - -out_unlock: - mutex_unlock(&indio_dev->mlock); - return ret; } static const struct iio_info adis16060_info = { -- 2.7.4