From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:48575 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753768AbdCVUdD (ORCPT ); Wed, 22 Mar 2017 16:33:03 -0400 Subject: Re: [PATCH] staging: ad7759: Replace mlock with driver private lock To: Arushi Singhal , lars@metafoo.de References: <20170320160926.GA7088@arushi-HP-Pavilion-Notebook> Cc: Michael Hennerich , 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 From: Jonathan Cameron Message-ID: <28e4d9ae-9159-0ab7-1958-1ea9f996646e@kernel.org> Date: Wed, 22 Mar 2017 20:33:00 +0000 MIME-Version: 1.0 In-Reply-To: <20170320160926.GA7088@arushi-HP-Pavilion-Notebook> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 20/03/17 16:09, Arushi 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: Arushi Singhal > --- > drivers/staging/iio/meter/ade7759.c | 4 ++-- > drivers/staging/iio/meter/ade7759.h | 1 + > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/iio/meter/ade7759.c b/drivers/staging/iio/meter/ade7759.c > index 944ee3401029..1d1e0b33021f 100644 > --- a/drivers/staging/iio/meter/ade7759.c > +++ b/drivers/staging/iio/meter/ade7759.c > @@ -381,7 +381,7 @@ static ssize_t ade7759_write_frequency(struct device *dev, > if (!val) > return -EINVAL; > > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&st->buf_lock); > > t = 27900 / val; > if (t > 0) > @@ -402,7 +402,7 @@ static ssize_t ade7759_write_frequency(struct device *dev, Deadlock as this call also take the buf_lock mutex.. > ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg); > > out: > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&st->buf_lock); > > return ret ? ret : len; > } > diff --git a/drivers/staging/iio/meter/ade7759.h b/drivers/staging/iio/meter/ade7759.h > index f0716d2fdf8e..4f69bb93cc45 100644 > --- a/drivers/staging/iio/meter/ade7759.h > +++ b/drivers/staging/iio/meter/ade7759.h > @@ -42,6 +42,7 @@ > * @buf_lock: mutex to protect tx and rx > * @tx: transmit buffer > * @rx: receive buffer > + * @lock protect sensor state ? > **/ > struct ade7759_state { > struct spi_device *us; >