Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753574AbdCVUZ4 (ORCPT ); Wed, 22 Mar 2017 16:25:56 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:48513 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753502AbdCVUZn (ORCPT ); Wed, 22 Mar 2017 16:25:43 -0400 Subject: Re: [PATCH v3 2/2] staging: iio: ade7753: Replace mlock with driver private lock To: simran singhal , lars@metafoo.de References: <1490119436-20042-1-git-send-email-singhalsimran0@gmail.com> <1490119436-20042-3-git-send-email-singhalsimran0@gmail.com> Cc: Michael.Hennerich@analog.com, knaack.h@gmx.de, pmeerw@pmeerw.net, gregkh@linuxfoundation.org, linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, outreachy-kernel@googlegroups.com From: Jonathan Cameron Message-ID: <5d65a41d-5290-eb55-6452-7bb8bfbdd9f2@kernel.org> Date: Wed, 22 Mar 2017 20:25:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <1490119436-20042-3-git-send-email-singhalsimran0@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1724 Lines: 51 On 21/03/17 18:03, simran singhal wrote: > 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. Replace it with a lock in the devices global data. > > Signed-off-by: simran singhal Mutex is not initialized... > --- > drivers/staging/iio/meter/ade7753.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/iio/meter/ade7753.c b/drivers/staging/iio/meter/ade7753.c > index b71fbd3..9674e05 100644 > --- a/drivers/staging/iio/meter/ade7753.c > +++ b/drivers/staging/iio/meter/ade7753.c > @@ -80,11 +80,13 @@ > * @us: actual spi_device > * @tx: transmit buffer > * @rx: receive buffer > + * @lock: protect sensor state > * @buf_lock: mutex to protect tx and rx > **/ > struct ade7753_state { > struct spi_device *us; > struct mutex buf_lock; > + struct mutex lock; /* protect sensor state */ > u8 tx[ADE7753_MAX_TX] ____cacheline_aligned; > u8 rx[ADE7753_MAX_RX]; > }; > @@ -484,7 +486,7 @@ static ssize_t ade7753_write_frequency(struct device *dev, > if (!val) > return -EINVAL; > > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&st->lock); > > t = 27900 / val; > if (t > 0) > @@ -505,7 +507,7 @@ static ssize_t ade7753_write_frequency(struct device *dev, > ret = ade7753_spi_write_reg_16(dev, ADE7753_MODE, reg); > > out: > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&st->lock); > > return ret ? ret : len; > } >