From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753277AbdATUZh (ORCPT ); Fri, 20 Jan 2017 15:25:37 -0500 Received: from mail-pg0-f67.google.com ([74.125.83.67]:34696 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753127AbdATUZe (ORCPT ); Fri, 20 Jan 2017 15:25:34 -0500 Date: Fri, 20 Jan 2017 12:22:58 -0800 From: Alison Schofield To: jic23@kernel.org Cc: tduszyns@gmail.com, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] iio: pressure: ms5611: claim direct mode during oversampling changes Message-ID: <20170120202242.GA2153@d830.WORKGROUP> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Driver was checking for direct mode before changing oversampling ratios, but was not locking it. Use the claim/release helper functions to guarantee the device stays in direct mode while the oversampling ratios are being updated. Continue to use the drivers private state lock to protect against conflicting direct mode access of the state data. Signed-off-by: Alison Schofield --- drivers/iio/pressure/ms5611_core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c index 6bd53e7..2a77a2f 100644 --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -308,6 +308,7 @@ static int ms5611_write_raw(struct iio_dev *indio_dev, { struct ms5611_state *st = iio_priv(indio_dev); const struct ms5611_osr *osr = NULL; + int ret; if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) return -EINVAL; @@ -321,12 +322,11 @@ static int ms5611_write_raw(struct iio_dev *indio_dev, if (!osr) return -EINVAL; - mutex_lock(&st->lock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; - if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&st->lock); - return -EBUSY; - } + mutex_lock(&st->lock); if (chan->type == IIO_TEMP) st->temp_osr = osr; @@ -334,6 +334,8 @@ static int ms5611_write_raw(struct iio_dev *indio_dev, st->pressure_osr = osr; mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + return 0; } -- 2.1.4